diff --git a/desmume/src/rasterize.cpp b/desmume/src/rasterize.cpp
index 8b2211206..3cfc85765 100644
--- a/desmume/src/rasterize.cpp
+++ b/desmume/src/rasterize.cpp
@@ -1246,7 +1246,10 @@ void SoftRasterizerEngine::framebufferProcess()
 		for(int i=0;i<8;i++)
 		{
 			u16 col = T1ReadWord(MMU.MMU_MEM[ARMCPU_ARM9][0x40], 0x330+i*2);
-			edgeMarkColors[i].color = RGB15TO5555(col,0x0F);
+			edgeMarkColors[i].color = RGB15TO5555(col,0x1F);
+			edgeMarkColors[i].r = GFX3D_5TO6(edgeMarkColors[i].r);
+			edgeMarkColors[i].g = GFX3D_5TO6(edgeMarkColors[i].g);
+			edgeMarkColors[i].b = GFX3D_5TO6(edgeMarkColors[i].b);
 
 			// this seems to be the only thing that selectively disables edge marking
 			edgeMarkDisabled[i] = (col == 0x7FFF);