diff --git a/radiantcore/shaders/Doom3ShaderLayer.cpp b/radiantcore/shaders/Doom3ShaderLayer.cpp
index a6affcddd3..db5382a2d8 100644
--- a/radiantcore/shaders/Doom3ShaderLayer.cpp
+++ b/radiantcore/shaders/Doom3ShaderLayer.cpp
@@ -224,17 +224,18 @@ const IShaderExpression::Ptr& Doom3ShaderLayer::getColourExpression(ColourCompon
     case COMP_ALPHA:
         return _expressionSlots[Expression::ColourAlpha].expression;
     case COMP_RGB:
-        // Select if all RGB are using the same expression
-        if (_expressionSlots[Expression::ColourRed].expression == _expressionSlots[Expression::ColourGreen].expression && 
-            _expressionSlots[Expression::ColourGreen].expression == _expressionSlots[Expression::ColourBlue].expression)
+        // Select if all RGB components are using equivalent expressions
+        if (_expressionSlots.expressionsAreEquivalent(Expression::ColourRed, Expression::ColourGreen) &&
+            _expressionSlots.expressionsAreEquivalent(Expression::ColourGreen, Expression::ColourBlue))
         {
             return _expressionSlots[Expression::ColourRed].expression;
         }
         break;
     case COMP_RGBA:
-        if (_expressionSlots[Expression::ColourRed].expression == _expressionSlots[Expression::ColourGreen].expression &&
-            _expressionSlots[Expression::ColourGreen].expression == _expressionSlots[Expression::ColourBlue].expression &&
-            _expressionSlots[Expression::ColourBlue].expression == _expressionSlots[Expression::ColourAlpha].expression)
+        // Select if all RGBA components are using equivalent expressions
+        if (_expressionSlots.expressionsAreEquivalent(Expression::ColourRed, Expression::ColourGreen) &&
+            _expressionSlots.expressionsAreEquivalent(Expression::ColourGreen, Expression::ColourBlue) &&
+            _expressionSlots.expressionsAreEquivalent(Expression::ColourBlue, Expression::ColourAlpha))
         {
             return _expressionSlots[Expression::ColourRed].expression;
         }
diff --git a/radiantcore/shaders/ExpressionSlots.cpp b/radiantcore/shaders/ExpressionSlots.cpp
index ec7a26af5b..c31daf444a 100644
--- a/radiantcore/shaders/ExpressionSlots.cpp
+++ b/radiantcore/shaders/ExpressionSlots.cpp
@@ -79,6 +79,24 @@ void ExpressionSlots::assignFromString(IShaderLayer::Expression::Slot slot, cons
     assign(slot, expression, defaultRegisterIndex);
 }
 
+bool ExpressionSlots::expressionsAreEquivalent(IShaderLayer::Expression::Slot slotA, IShaderLayer::Expression::Slot slotB) const
+{
+    auto a = at(slotA);
+    auto b = at(slotB);
+
+    if (a.expression == b.expression)
+    {
+        return true;
+    }
+
+    if (a.expression && b.expression)
+    {
+        return a.expression->getExpressionString() == b.expression->getExpressionString();
+    }
+
+    return false;
+}
+
 bool ExpressionSlots::registerIsShared(std::size_t index) const
 {
     std::size_t useCount = 0;
diff --git a/radiantcore/shaders/ExpressionSlots.h b/radiantcore/shaders/ExpressionSlots.h
index bfc39a8c3e..355027eb28 100644
--- a/radiantcore/shaders/ExpressionSlots.h
+++ b/radiantcore/shaders/ExpressionSlots.h
@@ -41,6 +41,11 @@ class ExpressionSlots :
     // Parsing failures of non-empty strings will not change the slot
     void assignFromString(IShaderLayer::Expression::Slot slot, const std::string& expression, std::size_t defaultRegisterIndex);
 
+    // Returns true if the two given slots are equipped with equivalent expressions 
+    // (i.e. are reference-equal or using the same string representation)
+    // This also returns true if both slots are empty
+    bool expressionsAreEquivalent(IShaderLayer::Expression::Slot slotA, IShaderLayer::Expression::Slot slotB) const;
+
 private:
     // Returns true if the given register index is in use by more than one expression
     bool registerIsShared(std::size_t index) const;
diff --git a/test/Materials.cpp b/test/Materials.cpp
index 7aaca314e0..762f997cf9 100644
--- a/test/Materials.cpp
+++ b/test/Materials.cpp
@@ -1082,4 +1082,82 @@ TEST_F(MaterialsTest, MaterialParserStageFlags)
     }
 }
 
+TEST_F(MaterialsTest, MaterialParserStageVertexColours)
+{
+    auto material = GlobalMaterialManager().getMaterial("textures/parsertest/vertexcolours/none");
+    EXPECT_EQ(material->getAllLayers().at(0)->getVertexColourMode(), IShaderLayer::VERTEX_COLOUR_NONE);
+    
+    material = GlobalMaterialManager().getMaterial("textures/parsertest/vertexcolours/vertexcolour");
+    EXPECT_EQ(material->getAllLayers().at(1)->getVertexColourMode(), IShaderLayer::VERTEX_COLOUR_INVERSE_MULTIPLY);
+    EXPECT_EQ(material->getAllLayers().at(0)->getVertexColourMode(), IShaderLayer::VERTEX_COLOUR_MULTIPLY);
+    
+    material = GlobalMaterialManager().getMaterial("textures/parsertest/vertexcolours/colourcomponents");
+
+    // Stage 1: Red
+    EXPECT_EQ(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_RED)->getExpressionString(), "0.5");
+    EXPECT_FALSE(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_GREEN));
+    EXPECT_FALSE(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_BLUE));
+    EXPECT_FALSE(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_ALPHA));
+    EXPECT_FALSE(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_RGB));
+    EXPECT_FALSE(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_RGBA));
+
+    // Stage 2: Green
+    EXPECT_EQ(material->getAllLayers().at(1)->getColourExpression(IShaderLayer::COMP_GREEN)->getExpressionString(), "0.4");
+    EXPECT_FALSE(material->getAllLayers().at(1)->getColourExpression(IShaderLayer::COMP_RED));
+    EXPECT_FALSE(material->getAllLayers().at(1)->getColourExpression(IShaderLayer::COMP_BLUE));
+    EXPECT_FALSE(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_ALPHA));
+    EXPECT_FALSE(material->getAllLayers().at(1)->getColourExpression(IShaderLayer::COMP_RGB));
+    EXPECT_FALSE(material->getAllLayers().at(1)->getColourExpression(IShaderLayer::COMP_RGBA));
+
+    // Stage 3: Blue
+    EXPECT_EQ(material->getAllLayers().at(2)->getColourExpression(IShaderLayer::COMP_BLUE)->getExpressionString(), "0.3");
+    EXPECT_FALSE(material->getAllLayers().at(2)->getColourExpression(IShaderLayer::COMP_RED));
+    EXPECT_FALSE(material->getAllLayers().at(2)->getColourExpression(IShaderLayer::COMP_GREEN));
+    EXPECT_FALSE(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_ALPHA));
+    EXPECT_FALSE(material->getAllLayers().at(2)->getColourExpression(IShaderLayer::COMP_RGB));
+    EXPECT_FALSE(material->getAllLayers().at(2)->getColourExpression(IShaderLayer::COMP_RGBA));
+
+    // Stage 4: Alpha
+    EXPECT_EQ(material->getAllLayers().at(3)->getColourExpression(IShaderLayer::COMP_ALPHA)->getExpressionString(), "0.2");
+    EXPECT_FALSE(material->getAllLayers().at(3)->getColourExpression(IShaderLayer::COMP_RED));
+    EXPECT_FALSE(material->getAllLayers().at(3)->getColourExpression(IShaderLayer::COMP_GREEN));
+    EXPECT_FALSE(material->getAllLayers().at(3)->getColourExpression(IShaderLayer::COMP_BLUE));
+    EXPECT_FALSE(material->getAllLayers().at(3)->getColourExpression(IShaderLayer::COMP_RGB));
+    EXPECT_FALSE(material->getAllLayers().at(3)->getColourExpression(IShaderLayer::COMP_RGBA));
+
+    material = GlobalMaterialManager().getMaterial("textures/parsertest/vertexcolours/combinations");
+
+    // Stage 1: RGB the same, alpha is different
+    EXPECT_EQ(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_RED)->getExpressionString(), "0.5");
+    EXPECT_EQ(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_GREEN)->getExpressionString(), "0.5");
+    EXPECT_EQ(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_BLUE)->getExpressionString(), "0.5");
+    EXPECT_EQ(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_ALPHA)->getExpressionString(), "time");
+    EXPECT_EQ(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_RGB)->getExpressionString(), "0.5");
+    EXPECT_FALSE(material->getAllLayers().at(0)->getColourExpression(IShaderLayer::COMP_RGBA));
+
+    // Stage 2: RGBA all the same
+    EXPECT_EQ(material->getAllLayers().at(1)->getColourExpression(IShaderLayer::COMP_RED)->getExpressionString(), "0.5");
+    EXPECT_EQ(material->getAllLayers().at(1)->getColourExpression(IShaderLayer::COMP_GREEN)->getExpressionString(), "0.5");
+    EXPECT_EQ(material->getAllLayers().at(1)->getColourExpression(IShaderLayer::COMP_BLUE)->getExpressionString(), "0.5");
+    EXPECT_EQ(material->getAllLayers().at(1)->getColourExpression(IShaderLayer::COMP_ALPHA)->getExpressionString(), "0.5");
+    EXPECT_EQ(material->getAllLayers().at(1)->getColourExpression(IShaderLayer::COMP_RGB)->getExpressionString(), "0.5");
+    EXPECT_EQ(material->getAllLayers().at(1)->getColourExpression(IShaderLayer::COMP_RGBA)->getExpressionString(), "0.5");
+
+    // Stage 3: RGB overridden by red
+    EXPECT_EQ(material->getAllLayers().at(2)->getColourExpression(IShaderLayer::COMP_RED)->getExpressionString(), "0.4");
+    EXPECT_EQ(material->getAllLayers().at(2)->getColourExpression(IShaderLayer::COMP_GREEN)->getExpressionString(), "0.3");
+    EXPECT_EQ(material->getAllLayers().at(2)->getColourExpression(IShaderLayer::COMP_BLUE)->getExpressionString(), "0.3");
+    EXPECT_FALSE(material->getAllLayers().at(2)->getColourExpression(IShaderLayer::COMP_ALPHA));
+    EXPECT_FALSE(material->getAllLayers().at(2)->getColourExpression(IShaderLayer::COMP_RGB));
+    EXPECT_FALSE(material->getAllLayers().at(2)->getColourExpression(IShaderLayer::COMP_RGBA));
+
+    // Stage 4: RGBA overridden by alpha
+    EXPECT_EQ(material->getAllLayers().at(3)->getColourExpression(IShaderLayer::COMP_RED)->getExpressionString(), "0.2");
+    EXPECT_EQ(material->getAllLayers().at(3)->getColourExpression(IShaderLayer::COMP_GREEN)->getExpressionString(), "0.2");
+    EXPECT_EQ(material->getAllLayers().at(3)->getColourExpression(IShaderLayer::COMP_BLUE)->getExpressionString(), "0.2");
+    EXPECT_EQ(material->getAllLayers().at(3)->getColourExpression(IShaderLayer::COMP_ALPHA)->getExpressionString(), "time");
+    EXPECT_EQ(material->getAllLayers().at(3)->getColourExpression(IShaderLayer::COMP_RGB)->getExpressionString(), "0.2");
+    EXPECT_FALSE(material->getAllLayers().at(3)->getColourExpression(IShaderLayer::COMP_RGBA));
+}
+
 }
diff --git a/test/resources/tdm/materials/parsertest.mtr b/test/resources/tdm/materials/parsertest.mtr
index ab1a6d743c..a6be547fab 100644
--- a/test/resources/tdm/materials/parsertest.mtr
+++ b/test/resources/tdm/materials/parsertest.mtr
@@ -765,3 +765,78 @@ textures/parsertest/stageflags/maskEverything
         maskDepth
 	}
 }
+
+textures/parsertest/vertexcolours/none
+{
+	diffusemap _white
+}
+
+textures/parsertest/vertexcolours/vertexcolour
+{
+	{
+		blend diffusemap
+		map _white
+        vertexColor
+	}
+    {
+		blend diffusemap
+		map _white
+        inverseVertexColor
+	}
+}
+
+textures/parsertest/vertexcolours/colourcomponents
+{
+	{
+		blend diffusemap
+		map _white
+        red 0.5
+	}
+    {
+		blend diffusemap
+		map _white
+        green 0.4
+	}
+    {
+		blend diffusemap
+		map _white
+        blue 0.3
+	}
+    {
+		blend diffusemap
+		map _white
+        alpha 0.2
+	}
+}
+
+textures/parsertest/vertexcolours/combinations
+{
+	{
+		blend diffusemap
+		map _white
+        red 0.5
+        green 0.5
+        blue 0.5
+        alpha time // alpha is different
+	}
+    {
+		blend diffusemap
+		map _white
+        red 0.5
+        green 0.5
+        blue 0.5
+        alpha 0.5
+	}
+    {
+		blend diffusemap
+		map _white
+        rgb 0.3
+        red 0.4
+	}
+    {
+		blend diffusemap
+		map _white
+        rgba 0.2
+        alpha time
+	}
+}