The Persil Color formulations are the best for colour care. I've used Cheer HE, it's not bad. I've also used some of the "green" detergents on dark colours, with pretty good results. I look for detergents that do not contain optical brighteners.
Right now i'm using Persil Megaperls, I like this one best overall, with the colour liquid a second and good for pretreating.
I,too, wish there were more choices for colour variant detergents.
I do add some white vinegar to the FS or bleach dispenser to help with colour care, as well. Todd