diff --git a/hecl/include/hecl/Backend/Metal.hpp b/hecl/include/hecl/Backend/Metal.hpp
index e7458c381..508c8cafa 100644
--- a/hecl/include/hecl/Backend/Metal.hpp
+++ b/hecl/include/hecl/Backend/Metal.hpp
@@ -40,6 +40,11 @@ private:
         return hecl::Format("float3(%g,%g,%g)", vec.vec[0], vec.vec[1], vec.vec[2]);
     }
 
+    std::string EmitColorRegUse(unsigned idx) const
+    {
+        return hecl::Format("lu.colorReg%u", idx);
+    }
+
     std::string EmitTexGenSource2(TexGenSrc src, int uvIdx) const;
     std::string EmitTexGenSource4(TexGenSrc src, int uvIdx) const;
 };
diff --git a/hecl/include/hecl/Backend/ProgrammableCommon.hpp b/hecl/include/hecl/Backend/ProgrammableCommon.hpp
index 1a2bbc9ce..c4e8c41ea 100644
--- a/hecl/include/hecl/Backend/ProgrammableCommon.hpp
+++ b/hecl/include/hecl/Backend/ProgrammableCommon.hpp
@@ -79,7 +79,7 @@ private:
         return hecl::Format("sampling%u.a", samplingIdx);
     }
 
-    std::string EmitColorRegUse(unsigned idx) const
+    virtual std::string EmitColorRegUse(unsigned idx) const
     {
         return hecl::Format("colorReg%u", idx);
     }