If someone wants to take the initiative to get up an order as Michael Kadillak did for the recent 8x20 B&W order, I'm sure color film could be had. Kodak's minimum order IIRC was $10,000 which isn't that much ULF film. It can be had, but no one wants very much at any given time, especially since there's more of a development issue with color.
The point is that film is made in master rolls, and if any film is available at all, then any format is at least theoretically available if you can convince the manufacturer to cut and package it in the format you want. Ilford and Kodak does this once a year at no extra charge for B&W, so there's no reason Kodak couldn't also do once a year color runs. But they won't do it for 5 boxes.