diff --git a/projects/mtg/include/CardDescriptor.h b/projects/mtg/include/CardDescriptor.h
index 648647a3f..058e9091a 100644
--- a/projects/mtg/include/CardDescriptor.h
+++ b/projects/mtg/include/CardDescriptor.h
@@ -11,6 +11,7 @@
 
 #define CD_OR 1
 #define CD_AND 2
+#define CD_NOT 3
 
 enum ENUM_COMPARISON_MODES
   {
@@ -23,10 +24,12 @@ enum ENUM_COMPARISON_MODES
     COMPARISON_UNEQUAL
   };
 
-class CardDescriptor: public MTGCardInstance{
+class CardDescriptor: public MTGCardInstance
+{
  protected:
-  MTGCardInstance * match_or(MTGCardInstance * card);
-  MTGCardInstance * match_and(MTGCardInstance * card);
+    MTGCardInstance * match_or(MTGCardInstance * card);
+    MTGCardInstance * match_and(MTGCardInstance * card);
+    MTGCardInstance * match_not(MTGCardInstance * card);
   bool valueInRange(int comparisonMode, int value, int criterion);
  public:
   int mode;
diff --git a/projects/mtg/include/CardPrimitive.h b/projects/mtg/include/CardPrimitive.h
index 1057cf7f4..f1d418c1b 100644
--- a/projects/mtg/include/CardPrimitive.h
+++ b/projects/mtg/include/CardPrimitive.h
@@ -11,6 +11,15 @@
 
 using namespace std;
 
+const uint8_t kColorBitMask_Artifact = 0x01;
+const uint8_t kColorBitMask_Green    = 0x02;
+const uint8_t kColorBitMask_Blue     = 0x04;
+const uint8_t kColorBitMask_Red      = 0x08;
+const uint8_t kColorBitMask_Black    = 0x10;
+const uint8_t kColorBitMask_White    = 0x20;
+const uint8_t kColorBitMask_Land     = 0x40;
+
+
 class CardPrimitive
 #ifdef TRACK_OBJECT_USAGE
     : public InstanceCounter<CardPrimitive>
@@ -25,7 +34,7 @@ public:
     string name;
     int init();
 
-    int colors[Constants::MTG_NB_COLORS];
+    uint8_t colors;
     map<int,int> basicAbilities;
     map<string,string> magicTexts;
     string magicText;
@@ -44,10 +53,10 @@ public:
     virtual ~CardPrimitive();
 
     void setColor(int _color, int removeAllOthers = 0);
-    void setColor(string _color, int removeAllOthers = 0);
+    void setColor(const string& _color, int removeAllOthers = 0);
     void removeColor(int color);
     int getColor();
-    int hasColor(int _color);
+    bool hasColor(int inColor);
     int countColors();
 
     int has(int ability);
@@ -70,11 +79,11 @@ public:
     int removeType(int value, int removeAll = 0);
     bool hasSubtype(int _subtype);
     bool hasSubtype(const char * _subtype);
-    bool hasSubtype(string _subtype);
+    bool hasSubtype(const string& _subtype);
     bool hasType(int _type);
     bool hasType(const char * type);
 
-    void setManaCost(string value);
+    void setManaCost(const string& value);
     ManaCost * getManaCost();
     bool isCreature();
     bool isLand();
diff --git a/projects/mtg/src/CardDescriptor.cpp b/projects/mtg/src/CardDescriptor.cpp
index 46d243ffc..9f7917896 100644
--- a/projects/mtg/src/CardDescriptor.cpp
+++ b/projects/mtg/src/CardDescriptor.cpp
@@ -101,6 +101,13 @@ bool CardDescriptor::valueInRange(int comparisonMode, int value, int criterion)
     return false;
 }
 
+MTGCardInstance* CardDescriptor::match_not(MTGCardInstance * card)
+{
+    // if we have a color match, return null
+    bool colorFound = (colors & card->colors) > 0;
+    return colorFound ? NULL : card;
+}
+
 MTGCardInstance * CardDescriptor::match_or(MTGCardInstance * card)
 {
     int found = 1;
@@ -128,27 +135,11 @@ MTGCardInstance * CardDescriptor::match_or(MTGCardInstance * card)
     if (!found)
         return NULL;
 
-    for (int i = 0; i < Constants::MTG_NB_COLORS; i++)
+    if (colors)
     {
-        if (colors[i] == 1)
-        {
-            found = 0;
-            if (card->hasColor(i))
-            {
-                found = 1;
-                break;
-            }
-        }
-        else if (colors[i] == -1)
-        {
-            found = 0;
-            if (!card->hasColor(i))
-            {
-                found = 1;
-                break;
-            }
-        }
+        found = (colors & card->colors);
     }
+
     if (!found)
         return NULL;
 
@@ -184,13 +175,8 @@ MTGCardInstance * CardDescriptor::match_and(MTGCardInstance * card)
             }
         }
     }
-    for (int i = 0; i < Constants::MTG_NB_COLORS; i++)
-    {
-        if ((colors[i] == 1 && !card->hasColor(i)) || (colors[i] == -1 && card->hasColor(i)))
-        {
-            match = NULL;
-        }
-    }
+    if ((colors & card->colors) != colors)
+        match = NULL;
 
     if (powerComparisonMode && !valueInRange(powerComparisonMode, card->getPower(), power))
         match = NULL;
@@ -200,21 +186,7 @@ MTGCardInstance * CardDescriptor::match_and(MTGCardInstance * card)
         match = NULL;
     if(nameComparisonMode && compareName != card->name)
         match = NULL;
-    if(colorComparisonMode)
-    {
-        bool hasMatch = false;
-        for (int i=0;i< Constants::MTG_NB_COLORS;i++) 
-        {
-            if (card->hasColor(i) && colors[i] > 0) 
-            {
-                hasMatch = true;
-            }
-        }
-        if( !hasMatch ) 
-        {
-            match = NULL;
-        }
-    }
+
     return match;
 }
 
@@ -226,10 +198,14 @@ MTGCardInstance * CardDescriptor::match(MTGCardInstance * card)
     {
         match = match_and(card);
     }
-    else
+    else if (mode == CD_OR)
     {
         match = match_or(card);
     }
+    else
+    {
+        match = match_not(card);
+    }
 
     //Abilities
     for (map<int, int>::const_iterator it = basicAbilities.begin(); it != basicAbilities.end(); ++it)
diff --git a/projects/mtg/src/CardPrimitive.cpp b/projects/mtg/src/CardPrimitive.cpp
index 24d1762fa..e16d67307 100644
--- a/projects/mtg/src/CardPrimitive.cpp
+++ b/projects/mtg/src/CardPrimitive.cpp
@@ -1,5 +1,6 @@
 #include "PrecompiledHeader.h"
 
+#include "MTGDefinitions.h"
 #include "CardPrimitive.h"
 
 #include "MTGDeck.h"
@@ -8,9 +9,68 @@
 
 using std::string;
 
+namespace
+{
+    uint8_t ConvertColorToBitMask(int inColor)
+    {
+        uint8_t value = 0;
+        switch (inColor)
+        {
+            case Constants::MTG_COLOR_ARTIFACT:
+                value = kColorBitMask_Artifact;
+                break;
+
+            case Constants::MTG_COLOR_GREEN:
+                 value = kColorBitMask_Green;
+                break;
+
+            case Constants::MTG_COLOR_BLUE:
+                value = kColorBitMask_Blue;
+                break;
+
+            case Constants::MTG_COLOR_RED:
+                value = kColorBitMask_Red;
+                break;
+
+            case Constants::MTG_COLOR_BLACK:
+                value = kColorBitMask_Black;
+                break;
+
+            case Constants::MTG_COLOR_WHITE:
+                value = kColorBitMask_White;
+                break;
+
+            case Constants::MTG_COLOR_LAND:
+                value = kColorBitMask_Land;
+                break;
+
+            default:
+                break;
+        }
+
+        return value;
+    }
+
+    /**
+    ** Count the number of set bits in a given integer 
+    */
+    int CountSetBits(int n)
+    {
+        int count = 0;
+        while (n)
+        {
+            n &= (n-1);
+            count++;
+        }
+        return count;
+    }
+}
+
+
 SUPPORT_OBJECT_ANALYTICS(CardPrimitive)
 
 CardPrimitive::CardPrimitive()
+    : colors(0)
 {
     init();
 }
@@ -22,8 +82,7 @@ CardPrimitive::CardPrimitive(CardPrimitive * source)
 
     for (size_t i = 0; i < source->types.size(); ++i)
         types.push_back(source->types[i]);
-    for (int i = 0; i < Constants::MTG_NB_COLORS; ++i)
-        colors[i] = source->colors[i];
+        colors = source->colors;
     manaCost.copy(source->getManaCost());
     //reducedCost.copy(source->getReducedManaCost());
     //increasedCost.copy(source->getIncreasedManaCost());
@@ -56,9 +115,6 @@ int CardPrimitive::init()
 
     types.clear();
 
-    for (int i = 0; i < Constants::MTG_NB_COLORS; ++i)
-        colors[i] = 0;
-
     magicText = "";
     magicTexts.clear();
     spellTargetType = "";
@@ -102,17 +158,17 @@ void CardPrimitive::getOtherRestrictions()
     otherrestriction;
 }
 
-void CardPrimitive::setColor(string _color, int removeAllOthers)
+void CardPrimitive::setColor(const string& _color, int removeAllOthers)
 {
-    if (_color.compare("blue") == 0)
+    if (_color.compare(Constants::kManaBlue) == 0)
         return setColor(Constants::MTG_COLOR_BLUE, removeAllOthers);
-    if (_color.compare("red") == 0)
+    if (_color.compare(Constants::kManaRed) == 0)
         return setColor(Constants::MTG_COLOR_RED, removeAllOthers);
-    if (_color.compare("green") == 0)
+    if (_color.compare(Constants::kManaGreen) == 0)
         return setColor(Constants::MTG_COLOR_GREEN, removeAllOthers);
-    if (_color.compare("black") == 0)
+    if (_color.compare(Constants::kManaBlack) == 0)
         return setColor(Constants::MTG_COLOR_BLACK, removeAllOthers);
-    if (_color.compare("white") == 0)
+    if (_color.compare(Constants::kManaWhite) == 0)
         return setColor(Constants::MTG_COLOR_WHITE, removeAllOthers);
     if (_color.compare("artifact") == 0)
         return setColor(Constants::MTG_COLOR_ARTIFACT, removeAllOthers);
@@ -121,39 +177,43 @@ void CardPrimitive::setColor(string _color, int removeAllOthers)
 void CardPrimitive::setColor(int _color, int removeAllOthers)
 {
     if (removeAllOthers)
-        for (int i = 0; i < Constants::MTG_NB_COLORS; i++)
-            colors[i] = 0;
-    colors[_color] = 1;
+        colors = 0;
+
+    colors |= ConvertColorToBitMask(_color);
 }
 
 void CardPrimitive::removeColor(int _color)
 {
-    colors[_color] = 0;
+    uint8_t mask = ~ConvertColorToBitMask(_color);
+    colors &= mask;
 }
 
 int CardPrimitive::getColor()
 {
-    for (int i = 1; i < Constants::MTG_NB_COLORS; i++)
-        if (colors[i])
-            return i;
+    if (colors)
+    {
+        for (int i = 1; i < Constants::MTG_NB_COLORS; i++)
+            if (hasColor(i))
+                return i;
+    }
+
     return 0;
 }
 
-int CardPrimitive::hasColor(int color)
+bool CardPrimitive::hasColor(int inColor)
 {
-    return (colors[color]);
+    return (colors & ConvertColorToBitMask(inColor)) > 0;
 }
 
 int CardPrimitive::countColors()
 {
-    int result = 0;
-    for (int i = Constants::MTG_COLOR_GREEN; i <= Constants::MTG_COLOR_WHITE; ++i)
-        if (hasColor(i))
-            ++result;
-    return result;
+    uint8_t mask = kColorBitMask_Green | kColorBitMask_Blue | kColorBitMask_Red | kColorBitMask_Black | kColorBitMask_White;
+    mask &= colors;
+
+    return CountSetBits(mask);
 }
 
-void CardPrimitive::setManaCost(string s)
+void CardPrimitive::setManaCost(const string& s)
 {
     ManaCost::parseManaCost(s, &manaCost);
     for (int i = Constants::MTG_COLOR_GREEN; i <= Constants::MTG_COLOR_WHITE; i++)
@@ -163,7 +223,6 @@ void CardPrimitive::setManaCost(string s)
             setColor(i);
         }
     }
-
 }
 
 void CardPrimitive::setType(const string& _type_text)
@@ -290,7 +349,7 @@ bool CardPrimitive::hasSubtype(const char * _subtype)
     return hasType(id);
 }
 
-bool CardPrimitive::hasSubtype(string _subtype)
+bool CardPrimitive::hasSubtype(const string& _subtype)
 {
     int id = Subtypes::subtypesList->find(_subtype);
     return hasType(id);
diff --git a/projects/mtg/src/MTGAbility.cpp b/projects/mtg/src/MTGAbility.cpp
index 9871ff2f2..58a700aa0 100644
--- a/projects/mtg/src/MTGAbility.cpp
+++ b/projects/mtg/src/MTGAbility.cpp
@@ -3113,8 +3113,7 @@ int AbilityFactory::getAbilities(vector<MTGAbility *> * v, Spell * spell, MTGCar
             card->setColor(0,1);
             card->name = card->model->data->name;
             card->types = card->model->data->types;
-            for (int i = 0; i < Constants::MTG_NB_COLORS; ++i)
-                card->colors[i] = card->model->data->colors[i];
+            card->colors = card->model->data->colors;
             for (map<int, int>::const_iterator it = card->model->data->basicAbilities.begin(); it != card->model->data->basicAbilities.end(); ++it)
             {
                 int i = it->first;
diff --git a/projects/mtg/src/MTGCardInstance.cpp b/projects/mtg/src/MTGCardInstance.cpp
index 7d63333c5..236f53544 100644
--- a/projects/mtg/src/MTGCardInstance.cpp
+++ b/projects/mtg/src/MTGCardInstance.cpp
@@ -62,10 +62,9 @@ void MTGCardInstance::copy(MTGCardInstance * card)
     {
         types.push_back(data->types[i]);
     }
-    for (int i = 0; i < Constants::MTG_NB_COLORS; i++)
-    {
-        colors[i] = data->colors[i];
-    }
+
+    colors = data->colors;
+
     manaCost.copy(data->getManaCost());
 
     text = data->text;
@@ -197,32 +196,33 @@ void MTGCardInstance::initMTGCI()
         }
     }
     int colored = 0;
-    
+
     for (int i = Constants::MTG_COLOR_GREEN; i <= Constants::MTG_COLOR_WHITE; ++i)
     {
         if (this->hasColor(i))
             ++colored;
     }
-    if(colored > 1)
+    if (colored > 1)
     {
         isMultiColored = 1;
+
+        if(this->hasColor(Constants::MTG_COLOR_WHITE) && this->hasColor(Constants::MTG_COLOR_BLACK))
+            isBlackAndWhite = 1;
+        if(this->hasColor(Constants::MTG_COLOR_RED) && this->hasColor(Constants::MTG_COLOR_BLUE))
+            isRedAndBlue = 1;
+        if(this->hasColor(Constants::MTG_COLOR_GREEN) && this->hasColor(Constants::MTG_COLOR_BLACK))
+            isBlackAndGreen = 1;
+        if(this->hasColor(Constants::MTG_COLOR_BLUE) && this->hasColor(Constants::MTG_COLOR_GREEN))
+            isBlueAndGreen = 1;
+        if(this->hasColor(Constants::MTG_COLOR_RED) && this->hasColor(Constants::MTG_COLOR_WHITE))
+            isRedAndWhite = 1;
+    }
+
+    if(previous && previous->morphed && !turningOver)
+    {
+        morphed = true;
+        isMorphed = true;
     }
-    
-    if(this->hasColor(Constants::MTG_COLOR_WHITE) && this->hasColor(Constants::MTG_COLOR_BLACK))
-        isBlackAndWhite = 1;
-    if(this->hasColor(Constants::MTG_COLOR_RED) && this->hasColor(Constants::MTG_COLOR_BLUE))
-        isRedAndBlue = 1;
-    if(this->hasColor(Constants::MTG_COLOR_GREEN) && this->hasColor(Constants::MTG_COLOR_BLACK))
-        isBlackAndGreen = 1;
-    if(this->hasColor(Constants::MTG_COLOR_BLUE) && this->hasColor(Constants::MTG_COLOR_GREEN))
-        isBlueAndGreen = 1;
-    if(this->hasColor(Constants::MTG_COLOR_RED) && this->hasColor(Constants::MTG_COLOR_WHITE))
-        isRedAndWhite = 1;
- if(previous && previous->morphed && !turningOver)
- {
- morphed = true;
- isMorphed = true;
- }
 }
 
 const string MTGCardInstance::getDisplayName() const
diff --git a/projects/mtg/src/TargetChooser.cpp b/projects/mtg/src/TargetChooser.cpp
index 286fd22df..00f9fc959 100644
--- a/projects/mtg/src/TargetChooser.cpp
+++ b/projects/mtg/src/TargetChooser.cpp
@@ -507,13 +507,11 @@ TargetChooser * TargetChooserFactory::createTargetChooser(string s, MTGCardInsta
                     }
                     else if( CDtype.find("color") != string::npos )
                     {
-                        for(int i = 0; i < Constants::MTG_NB_COLORS; i++)
-                        {
-                            if(card->target)
-                                cd->colors[i] = card->target->colors[i];
-                            else
-                                cd->colors[i] = card->colors[i];
-                        }
+                        if(card->target)
+                            cd->colors = card->target->colors;
+                        else
+                            cd->colors = card->colors;
+                       
                         cd->mode = CD_OR;
                     }
                     else if( CDtype.find("types") != string::npos )
@@ -571,20 +569,17 @@ TargetChooser * TargetChooserFactory::createTargetChooser(string s, MTGCardInsta
                 else
                 {
                     int attributefound = 0;
-                    //Colors
+                    //Colors - remove Artifact and Land from the loop
                     for (int cid = 1; cid < Constants::MTG_NB_COLORS - 1; cid++)
-                    { //remove Artifact and Land from the loop
+                    { 
                         if (attribute.find(Constants::MTGColorStrings[cid]) != string::npos)
                         {
                             attributefound = 1;
                             if (minus)
                             {
-                                cd->colors[cid] = -1;
-                            }
-                            else
-                            {
-                                cd->colors[cid] = 1;
+                                cd->mode = CD_NOT;
                             }
+                            cd->setColor(cid);
                         }
                     }
                     if (!attributefound)
@@ -621,7 +616,8 @@ TargetChooser * TargetChooserFactory::createTargetChooser(string s, MTGCardInsta
                     }
                 }
             }
-            if (nbminuses) cd->mode = CD_AND;
+            if (nbminuses && cd->mode != CD_NOT)
+                cd->mode = CD_AND;
             typeName = typeName.substr(0, found);
         }
         //X targets allowed ?
diff --git a/projects/mtg/src/WFilter.cpp b/projects/mtg/src/WFilter.cpp
index 4bd15e8dd..dbb4188f1 100644
--- a/projects/mtg/src/WFilter.cpp
+++ b/projects/mtg/src/WFilter.cpp
@@ -211,7 +211,7 @@ string WCFilterSet::getCode()
 bool WCFilterColor::isMatch(MTGCard * c)
 {
     if (!c || !c->data) return false;
-    return (c->data->hasColor(color) > 0);
+    return (c->data->hasColor(color));
 }
 string WCFilterColor::getCode()
 {
@@ -242,9 +242,9 @@ bool WCFilterOnlyColor::isMatch(MTGCard * c)
     for (int i = 0; i < Constants::MTG_NB_COLORS; i++)
     {
         if (i == color) continue;
-        if (c->data->hasColor(i) > 0) return false;
+        if (c->data->hasColor(i)) return false;
     }
-    return (c->data->hasColor(color) > 0);
+    return (c->data->hasColor(color));
 }
 string WCFilterOnlyColor::getCode()
 {