diff --git a/desmume/src/utils/colorspacehandler/colorspacehandler_AltiVec.cpp b/desmume/src/utils/colorspacehandler/colorspacehandler_AltiVec.cpp
index 752154b6d..9c20dbd5e 100644
--- a/desmume/src/utils/colorspacehandler/colorspacehandler_AltiVec.cpp
+++ b/desmume/src/utils/colorspacehandler/colorspacehandler_AltiVec.cpp
@@ -207,7 +207,19 @@ FORCEINLINE v128u16 _ConvertColorBaseTo5551_AltiVec(const v128u32 &srcLo, const
 	// Convert alpha
 	dstAlpha = vec_packsu( vec_and(srcLo, ((v128u32){0x000000FF,0x000000FF,0x000000FF,0x000000FF})), vec_and(srcHi, ((v128u32){0x000000FF,0x000000FF,0x000000FF,0x000000FF})) );
 	dstAlpha = vec_cmpgt( dstAlpha, vec_splat_u16(0) );
-	dstAlpha = vec_and( dstAlpha, ((v128u16){0x8000,0x8000,0x8000,0x8000,0x8000,0x8000,0x8000,0x8000}) );
+	
+	if (COLORFORMAT == NDSColorFormat_BGR666_Rev)
+	{
+		dstAlpha = vec_and( dstAlpha, ((v128u16){0x8000,0x8000,0x8000,0x8000,0x8000,0x8000,0x8000,0x8000}) );
+	}
+	else if (COLORFORMAT == NDSColorFormat_BGR888_Rev)
+	{
+		// TODO: Don't know why RGBA8888 colors need to swap bytes for the final 16-bit color
+		// when RGBA6665 colors don't need to, but real-world testing shows that RGBA8888 colors
+		// need to do this. Further testing is needed to find out why this byte swap is necessary.
+		// - rogerman, 2025/07/19
+		dstAlpha = vec_and( dstAlpha, ((v128u16){0x0080,0x0080,0x0080,0x0080,0x0080,0x0080,0x0080,0x0080}) );
+	}
 	
 	// Convert RGB
 	if (SWAP_RB)
@@ -221,8 +233,17 @@ FORCEINLINE v128u16 _ConvertColorBaseTo5551_AltiVec(const v128u32 &srcLo, const
 		rgbHi = vec_perm( (v128u8)rgbHi, (v128u8)rgbHi, ((v128u8){3,2,1,0,  7,6,5,4,  11,10,9,8,  15,14,13,12}) );
 	}
 	
+	// Convert from 32-bit color to 16-bit color using the built-in AltiVec instruction vpkpx.
 	dstColor = (v128u16)vec_packpx(rgbLo, rgbHi);
-	dstColor = vec_and( dstColor, ((v128u16){0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF}) );
+	
+	if (COLORFORMAT == NDSColorFormat_BGR666_Rev)
+	{
+		dstColor = vec_and( dstColor, ((v128u16){0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF,0x7FFF}) );
+	}
+	else if (COLORFORMAT == NDSColorFormat_BGR888_Rev)
+	{
+		dstColor = vec_and( dstColor, ((v128u16){0xFF7F,0xFF7F,0xFF7F,0xFF7F,0xFF7F,0xFF7F,0xFF7F,0xFF7F}) );
+	}
 	
 	return (v128u16)vec_or( (v128u8)dstColor, (v128u8)dstAlpha );
 }