Sometimes, tiny food just doesn't turn out the way you'd hoped. Or you forget to thoroughly wash your hands between the dark red and white clays and end up with pink sesame seeds. Or that color mixing experiment you tried just didn't come out the way you'd hoped. Or you finish a project and end up with some weird leftovers. The longer you work with clay, the more little random bits of "off" colors you'll generate.
When individual colors are not salvageable, we tend to squish everything together into a pile of ambiguous mush. It generally turns into a brownish, oliveish, pinkish mass that looks thoroughly unappetizing. The clay isn't bad- just not useful for making tiny food (unless perhaps you're making an MRE or those sad green beans from school cafeterias). There's no reason to throw it out. You just need to get creative in how to use it!
Our favorite way to use up ambiguous mush is to hide it inside of larger pieces. Basically, if your piece won't be sliced open (such as a pie), then there's no reason you can't cover an ugly color with a beautiful one. You'll want to use a thinnish layer to cover the mush. Make sure the covering layer is not too thin or too much lighter, otherwise the mush color will show through.
Cover the mush completely, making sure that none of the mush color is showing through the top layer. You don't need to worry too much about making the top layer a perfectly uniform thickness. The main thing is to make sure the top layer is completely covering that underneath.
Roll the whole ball completely smooth. At this point, it's best to immediately sculpt the finished piece you have in mind. Why? Because a covered ball is indistinguishable from a pure color. It's very easy to forget that you've created a covered ball, and next thing you know, you'll grab it, pinch off a bit and realize that that lovely ball of black is not indeed just black! (We speak from much experience here.)
Et voila! A finished sushi platter with a bunch of very olive-colored clay in the middle, and no one (unless they read this post!) will ever be the wiser.