Thanks GFW!

src/ImageSharp/ColorSpaces/Conversion/Implementation/YCbCr/YCbCrAndRgbConverter.cs

@@ -29,6 +29,9 @@ namespace ImageSharp.ColorSpaces.Conversion.Implementation.YCbCr
             float cb = input.Cb - 128F;
             float cr = input.Cr - 128F;
 
+            float r = MathF.Round(y + (1.402F * cr), MidpointRounding.AwayFromZero);
+            float g = MathF.Round(y - (0.344136F * cb) - (0.714136F * cr), MidpointRounding.AwayFromZero);
+            float b = MathF.Round(y + (1.772F * cb), MidpointRounding.AwayFromZero);
 
             return new Rgb(new Vector3(r, g, b) / MaxBytes);
         }
@@ -45,8 +48,10 @@ namespace ImageSharp.ColorSpaces.Conversion.Implementation.YCbCr
             float b = rgb.Z;
 
             float y = (0.299F * r) + (0.587F * g) + (0.114F * b);
+            float cb = 128F + ((-0.168736F * r) - (0.331264F * g) + (0.5F * b));
+            float cr = 128F + ((0.5F * r) - (0.418688F * g) - (0.081312F * b));
 
             return new YCbCr(y, cb, cr);
         }
     }
-}
+}