Hmmm... dye from cat treats enveloped in vomit. Gooooood one!
Have you tried Resolve Triple Action? I swear it's miracle stuff. It may not neutralize the odor (use Nature's Miracle for that) but it SHOULD take out the coloring if you can catch it while it's wet.
Or are we talking "already dried" here?
I don't think they make the Orange Glo company's Orange Eliminator anymore but it was awesome carpet cleaner. One can never went very far, but man--good stuff. I swore they should've made it for a carpet steam machine. But that was 10 years ago and I haven't seen it since.