Color negative in Rodinal gives a grainy result compared to B/W neg of the same speed.I developed Kodak 800 ISO color negative film exposed at EI=400 in Rodinal 1:50,see attached.This test was developed for 14m 68F but the negative was low contrast,something like 22m 68F agitate 10s/min might be better for Rodinal 1:50.There was no problem with 5 min fix time.
You could bleach this with a ferricyanide bleach (that's what's in sepia toner packs, right?), then expose to bright light and redevelop to completion in either C-41 or E-6 developer (second developer if using E-6).
Obviously your colour fidelity won't be 100%, but you'll be able to recover some colour information in this way.
I have done this using ancient (~half a century old) Gevaert film with colour images recovered. Obviously they were not top quality, having sat around as latent images for a couple of generations then been developed in the wrong chemicals, but still. I suspect that your results might be a bit better.
If you don't get enough dye formed, you can always re-bleach and re-develop to make more dye. Once you blix (or bleach then fix) your silver image goes and you're left with only dye, which doesn't react with developer any more.