For CP, you need to make sure the colors you use are stable in the high PH batter or it could morph into a grey or brown color. Many M&P colors don't work well in CP. You generally need more color for CP and if you use mica, it won't be shimmery in CP.
I don't do M&P but I suppose as to actually adding the color, its fairly similar to CP. With CP, you add the color then blend it in with your SB, with M&P it mixes in easier. Not sure if thats the info you are looking for or not.