What is True Color Paint?

They sell their own thinner. But you can thin it with Acetone. Pretty much the only solvent based railroad paint you can still purchase. They have an extensive line of RR specific colors.

You can use acetone but its dries very fast, maybe too fast to get a smooth finish. Lacquer thinner can be used as well and will dry slower, a bit easier to use.

Pete

I’ve tried several paints and have been the happiest with Trucolor. I use their thinner and retarder to keep it from drying before it hits the object. Best railroad color selection but also the most expensive. As others have said, it cleans up really nice with acetone

If you need to thin it, use their thinner.  It’s got something beyond acetone in it that makes it act different.  Clean it up with acetone though, it’s cheaper.

I still rely on Scale Coat 2.

Dick

Tru-color rocks! Goes on right out of the bottle, dries almost instantly, and their colors are great. Only problem I've had is with some bottles I picked up at a LHS, no telling how long they'd sat there, and apparently some of the solvent had evaporated, leaving it too thick to shoot cleanly. A bit of their thinner fixed it right up. I've heard they changed the design of the bottles to help prevent this, but I still order from Arizona Hobbies who seem to get it fresh from them. Cleans up great with acetone.