Can you tint ABS plastic?

if you don't mind wasting a roll, put a roll in a 5 gallon bucket. Fill it up with water just above the top of the spool. Add moderate amount of food coloring and stir. Let sit for an hour. Remove spool and shake off excess water. Put in oven at 175F for 4 hours. Remove and check diameter to make sure the filament hasn't retained any water. Print and then let us know if it worked.

(I will not take any responsibility for damage to the filament or your printer.)

In my military figure customizing hobby, I've used RIT dye in boiling water to dye figures and vehicles.  Granted, these are usually made of PVC, but I've used the method on Styrene, so it should work on ABS.  The key is to get the water to boiling, add in the dye, then let it cool some before adding the part to avoid warping.  The warmer the water, the faster the dye will set, but if you're worried about the heat warping a part, you can use cooler water, but you'll have to let the part soak for longer periods.

water based dyes work well on nylon

I don't think abs tints that well...Would love to hear more, though.

Maybe two birds with one stone?  A dying/smoothing station that uses a tinted acetone/water mix to smooth the object?