Some of my color paste has thickened. How do I loosen it up?
I noticed a couple weeks ago that my bottle of glycerin said it was for restoring the texture of gel food colors. I haven't tried it yet, but maybe you should try adding some glycerin to your colors that have thickened?
Yes, you can add some glycerin. I find that the results are transitory and sometimes you still get little flecks of color that will no longer dissolve. It's worth a try, though.
Since glycerin isn't that cheap, it's often just as well to go buy the new colors.
if your colour is just gummy then stiring glycerine in will restore it, but if there is any signs of crystalization, crunchy flecks, throw it way, you will never get rid of them. It is cheaper to just buy new colours.