Color coded coffee

I'm no coffee professional, but I figure a big factor in whether or not you want to drink it is the color. Especially if you're mixing sugar and cream and dramatically altering the color it starts at. But what happens when you drink half a cup and then it gets refilled? Well now the whole ratio is screwed up. Well this is a kind of fun idea to fix that problem.

It's a coffee mug, but on the inside are colored sections. Mostly just different shades of brown. Once you mix your coffee the way you like it, just note the closest color comparison on the inside of the cup. Now anytime that color gets changed (if it gets refilled half way through) all you have to do is match to that original color you selected. Seems like it might be occasionally handy and fun every once in a while.