Able to dye acrylic yarn or remove color?

I am new to the knitting forum and I wonder if someone can help with this question?
I have been knitting for years but have never attempted to dye or remove color from yarn. Is it possible to do either with acrylic yarn with any success?

My only experience with dying is with Koolaid. I know koolaid will only work on wool/hair from animals. It won’t work on cotton or acrylic… it stains, rather than dyes.

Procion dyes only work on natural fibers.
Rit dyes work on some synthetics, but may only produce a light tint, not a rich color. There’s a fabric dyeing chart on their web site:

http://www.ritdye.com/a.asp#select