diff --git a/Source/Core/VideoBackends/D3D/PixelShaderCache.cpp b/Source/Core/VideoBackends/D3D/PixelShaderCache.cpp
index 5364c58cdd..6b62e1575f 100644
--- a/Source/Core/VideoBackends/D3D/PixelShaderCache.cpp
+++ b/Source/Core/VideoBackends/D3D/PixelShaderCache.cpp
@@ -104,7 +104,7 @@ const char color_matrix_program_code[] = {"sampler samp0 : register(s0);\n"
                                           "in float4 pos : SV_Position,\n"
                                           "in float3 uv0 : TEXCOORD0){\n"
                                           "float4 texcol = Tex0.Sample(samp0,uv0);\n"
-                                          "texcol = round(texcol * cColMatrix[5])*cColMatrix[6];\n"
+                                          "texcol = floor(texcol * cColMatrix[5])*cColMatrix[6];\n"
                                           "ocol0 = "
                                           "float4(dot(texcol,cColMatrix[0]),dot(texcol,cColMatrix["
                                           "1]),dot(texcol,cColMatrix[2]),dot(texcol,cColMatrix[3]))"
@@ -126,7 +126,7 @@ const char color_matrix_program_code_msaa[] = {
     "for(int i = 0; i < SAMPLES; ++i)\n"
     "	texcol += Tex0.Load(int3(uv0.x*(width), uv0.y*(height), uv0.z), i);\n"
     "texcol /= SAMPLES;\n"
-    "texcol = round(texcol * cColMatrix[5])*cColMatrix[6];\n"
+    "texcol = floor(texcol * cColMatrix[5])*cColMatrix[6];\n"
     "ocol0 = "
     "float4(dot(texcol,cColMatrix[0]),dot(texcol,cColMatrix[1]),dot(texcol,cColMatrix[2]),dot("
     "texcol,cColMatrix[3])) + cColMatrix[4];\n"
diff --git a/Source/Core/VideoBackends/D3D12/StaticShaderCache.cpp b/Source/Core/VideoBackends/D3D12/StaticShaderCache.cpp
index 652b1515ba..0535c7c05a 100644
--- a/Source/Core/VideoBackends/D3D12/StaticShaderCache.cpp
+++ b/Source/Core/VideoBackends/D3D12/StaticShaderCache.cpp
@@ -131,7 +131,7 @@ static constexpr const char s_color_matrix_program_hlsl[] = {
     "in float4 pos : SV_Position,\n"
     "in float3 uv0 : TEXCOORD0){\n"
     "float4 texcol = Tex0.Sample(samp0,uv0);\n"
-    "texcol = round(texcol * cColMatrix[5])*cColMatrix[6];\n"
+    "texcol = floor(texcol * cColMatrix[5])*cColMatrix[6];\n"
     "ocol0 = "
     "float4(dot(texcol,cColMatrix[0]),dot(texcol,cColMatrix[1]),dot(texcol,cColMatrix[2]),dot("
     "texcol,cColMatrix[3])) + cColMatrix[4];\n"
@@ -152,7 +152,7 @@ static constexpr const char s_color_matrix_program_msaa_hlsl[] = {
     "for(int i = 0; i < SAMPLES; ++i)\n"
     "	texcol += Tex0.Load(int3(uv0.x*(width), uv0.y*(height), uv0.z), i);\n"
     "texcol /= SAMPLES;\n"
-    "texcol = round(texcol * cColMatrix[5])*cColMatrix[6];\n"
+    "texcol = floor(texcol * cColMatrix[5])*cColMatrix[6];\n"
     "ocol0 = "
     "float4(dot(texcol,cColMatrix[0]),dot(texcol,cColMatrix[1]),dot(texcol,cColMatrix[2]),dot("
     "texcol,cColMatrix[3])) + cColMatrix[4];\n"
diff --git a/Source/Core/VideoBackends/OGL/TextureCache.cpp b/Source/Core/VideoBackends/OGL/TextureCache.cpp
index dc9d290f3e..50c729d45e 100644
--- a/Source/Core/VideoBackends/OGL/TextureCache.cpp
+++ b/Source/Core/VideoBackends/OGL/TextureCache.cpp
@@ -333,7 +333,7 @@ bool TextureCache::CompileShaders()
       "\n"
       "void main(){\n"
       "	vec4 texcol = texture(samp9, f_uv0);\n"
-      "	texcol = round(texcol * colmat[5]) * colmat[6];\n"
+      "	texcol = floor(texcol * colmat[5]) * colmat[6];\n"
       "	ocol0 = texcol * mat4(colmat[0], colmat[1], colmat[2], colmat[3]) + colmat[4];\n"
       "}\n";
 
diff --git a/Source/Core/VideoBackends/Software/TextureEncoder.cpp b/Source/Core/VideoBackends/Software/TextureEncoder.cpp
index dcb29de2a5..ae6905f1c2 100644
--- a/Source/Core/VideoBackends/Software/TextureEncoder.cpp
+++ b/Source/Core/VideoBackends/Software/TextureEncoder.cpp
@@ -335,7 +335,7 @@ static void EncodeRGBA6(u8* dst, const u8* src, u32 format)
       src += readStride;
 
       u16 val =
-          ((srcColor >> 8) & 0xf800) | ((srcColor >> 7) & 0x07e0) | ((srcColor >> 7) & 0x001e);
+          ((srcColor >> 8) & 0xf800) | ((srcColor >> 7) & 0x07e0) | ((srcColor >> 7) & 0x001f);
       *(u16*)dst = Common::swap16(val);
       dst += 2;
     }
@@ -354,7 +354,7 @@ static void EncodeRGBA6(u8* dst, const u8* src, u32 format)
       u16 val;
       if (alpha == 0x7000)  // 555
         val = 0x8000 | ((srcColor >> 9) & 0x7c00) | ((srcColor >> 8) & 0x03e0) |
-              ((srcColor >> 7) & 0x001e);
+              ((srcColor >> 7) & 0x001f);
       else  // 4443
         val = alpha | ((srcColor >> 12) & 0x0f00) | ((srcColor >> 10) & 0x00f0) |
               ((srcColor >> 8) & 0x000f);
@@ -573,7 +573,7 @@ static void EncodeRGBA6halfscale(u8* dst, const u8* src, u32 format)
       BoxfilterRGBA_to_RGB8(src, &r, &g, &b);
       src += readStride;
 
-      u16 val = ((r << 8) & 0xf800) | ((g << 3) & 0x07e0) | ((b >> 3) & 0x001e);
+      u16 val = ((r << 8) & 0xf800) | ((g << 3) & 0x07e0) | ((b >> 3) & 0x001f);
       *(u16*)dst = Common::swap16(val);
       dst += 2;
     }
@@ -590,7 +590,7 @@ static void EncodeRGBA6halfscale(u8* dst, const u8* src, u32 format)
 
       u16 val;
       if (a >= 224)  // 5551
-        val = 0x8000 | ((r << 7) & 0x7c00) | ((g << 2) & 0x03e0) | ((b >> 3) & 0x001e);
+        val = 0x8000 | ((r << 7) & 0x7c00) | ((g << 2) & 0x03e0) | ((b >> 3) & 0x001f);
       else  // 4443
         val = ((a << 7) & 0x7000) | ((r << 4) & 0x0f00) | (g & 0x00f0) | ((b >> 4) & 0x000f);
 
@@ -800,7 +800,7 @@ static void EncodeRGB8(u8* dst, const u8* src, u32 format)
     SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
     ENCODE_LOOP_BLOCKS
     {
-      u16 val = ((src[2] << 8) & 0xf800) | ((src[1] << 3) & 0x07e0) | ((src[0] >> 3) & 0x001e);
+      u16 val = ((src[2] << 8) & 0xf800) | ((src[1] << 3) & 0x07e0) | ((src[0] >> 3) & 0x001f);
       *(u16*)dst = Common::swap16(val);
       src += readStride;
       dst += 2;
@@ -814,7 +814,7 @@ static void EncodeRGB8(u8* dst, const u8* src, u32 format)
     ENCODE_LOOP_BLOCKS
     {
       u16 val =
-          0x8000 | ((src[2] << 7) & 0x7c00) | ((src[1] << 2) & 0x03e0) | ((src[0] >> 3) & 0x001e);
+          0x8000 | ((src[2] << 7) & 0x7c00) | ((src[1] << 2) & 0x03e0) | ((src[0] >> 3) & 0x001f);
       *(u16*)dst = Common::swap16(val);
       src += readStride;
       dst += 2;
@@ -1018,7 +1018,7 @@ static void EncodeRGB8halfscale(u8* dst, const u8* src, u32 format)
     ENCODE_LOOP_BLOCKS
     {
       BoxfilterRGB_to_RGB8(src, &r, &g, &b);
-      u16 val = ((r << 8) & 0xf800) | ((g << 3) & 0x07e0) | ((b >> 3) & 0x001e);
+      u16 val = ((r << 8) & 0xf800) | ((g << 3) & 0x07e0) | ((b >> 3) & 0x001f);
       *(u16*)dst = Common::swap16(val);
       src += readStride;
       dst += 2;
@@ -1032,7 +1032,7 @@ static void EncodeRGB8halfscale(u8* dst, const u8* src, u32 format)
     ENCODE_LOOP_BLOCKS
     {
       BoxfilterRGB_to_RGB8(src, &r, &g, &b);
-      u16 val = 0x8000 | ((r << 7) & 0x7c00) | ((g << 2) & 0x03e0) | ((b >> 3) & 0x001e);
+      u16 val = 0x8000 | ((r << 7) & 0x7c00) | ((g << 2) & 0x03e0) | ((b >> 3) & 0x001f);
       *(u16*)dst = Common::swap16(val);
       src += readStride;
       dst += 2;
diff --git a/Source/Core/VideoBackends/Vulkan/TextureCache.cpp b/Source/Core/VideoBackends/Vulkan/TextureCache.cpp
index b08ae89f91..a860e8601d 100644
--- a/Source/Core/VideoBackends/Vulkan/TextureCache.cpp
+++ b/Source/Core/VideoBackends/Vulkan/TextureCache.cpp
@@ -602,7 +602,7 @@ bool TextureCache::CompileShaders()
     void main()
     {
       float4 texcol = texture(samp0, uv0);
-      texcol = round(texcol * C.colmat[5]) * C.colmat[6];
+      texcol = floor(texcol * C.colmat[5]) * C.colmat[6];
       ocol0 = texcol * mat4(C.colmat[0], C.colmat[1], C.colmat[2], C.colmat[3]) + C.colmat[4];
     }
   )";
diff --git a/Source/Core/VideoCommon/TextureCacheBase.cpp b/Source/Core/VideoCommon/TextureCacheBase.cpp
index 9b5df69627..47ecc4f528 100644
--- a/Source/Core/VideoCommon/TextureCacheBase.cpp
+++ b/Source/Core/VideoCommon/TextureCacheBase.cpp
@@ -1039,7 +1039,7 @@ void TextureCacheBase::CopyRenderTargetToTexture(u32 dstAddr, unsigned int dstFo
         fConstAdd[3] = 16.0f / 255.0f;
         if (dstFormat == 0)
         {
-          ColorMask[0] = ColorMask[1] = ColorMask[2] = 15.0f;
+          ColorMask[0] = ColorMask[1] = ColorMask[2] = 255.0f / 16.0f;
           ColorMask[4] = ColorMask[5] = ColorMask[6] = 1.0f / 15.0f;
           cbufid = 9;
         }
@@ -1053,7 +1053,7 @@ void TextureCacheBase::CopyRenderTargetToTexture(u32 dstAddr, unsigned int dstFo
         colmat[15] = 1;
         if (dstFormat == 2)
         {
-          ColorMask[0] = ColorMask[1] = ColorMask[2] = ColorMask[3] = 15.0f;
+          ColorMask[0] = ColorMask[1] = ColorMask[2] = ColorMask[3] = 255.0f / 16.0f;
           ColorMask[4] = ColorMask[5] = ColorMask[6] = ColorMask[7] = 1.0f / 15.0f;
           cbufid = 11;
         }
@@ -1077,7 +1077,7 @@ void TextureCacheBase::CopyRenderTargetToTexture(u32 dstAddr, unsigned int dstFo
     {
     case 0:  // R4
       colmat[0] = colmat[4] = colmat[8] = colmat[12] = 1;
-      ColorMask[0] = 15.0f;
+      ColorMask[0] = 255.0f / 16.0f;
       ColorMask[4] = 1.0f / 15.0f;
       cbufid = 14;
       dstFormat |= _GX_TF_CTF;
@@ -1091,7 +1091,7 @@ void TextureCacheBase::CopyRenderTargetToTexture(u32 dstAddr, unsigned int dstFo
 
     case 2:  // RA4
       colmat[0] = colmat[4] = colmat[8] = colmat[15] = 1.0f;
-      ColorMask[0] = ColorMask[3] = 15.0f;
+      ColorMask[0] = ColorMask[3] = 255.0f / 16.0f;
       ColorMask[4] = ColorMask[7] = 1.0f / 15.0f;
 
       cbufid = 16;
@@ -1157,9 +1157,9 @@ void TextureCacheBase::CopyRenderTargetToTexture(u32 dstAddr, unsigned int dstFo
 
     case 4:  // RGB565
       colmat[0] = colmat[5] = colmat[10] = 1.0f;
-      ColorMask[0] = ColorMask[2] = 31.0f;
+      ColorMask[0] = ColorMask[2] = 255.0f / 8.0f;
       ColorMask[4] = ColorMask[6] = 1.0f / 31.0f;
-      ColorMask[1] = 63.0f;
+      ColorMask[1] = 255.0f / 4.0f;
       ColorMask[5] = 1.0f / 63.0f;
       fConstAdd[3] = 1.0f;  // set alpha to 1
       cbufid = 26;
@@ -1167,9 +1167,9 @@ void TextureCacheBase::CopyRenderTargetToTexture(u32 dstAddr, unsigned int dstFo
 
     case 5:  // RGB5A3
       colmat[0] = colmat[5] = colmat[10] = colmat[15] = 1.0f;
-      ColorMask[0] = ColorMask[1] = ColorMask[2] = 31.0f;
+      ColorMask[0] = ColorMask[1] = ColorMask[2] = 255.0f / 8.0f;
       ColorMask[4] = ColorMask[5] = ColorMask[6] = 1.0f / 31.0f;
-      ColorMask[3] = 7.0f;
+      ColorMask[3] = 255.0f / 32.0f;
       ColorMask[7] = 1.0f / 7.0f;
 
       cbufid = 27;