was trying to color a black and red fondant, had to use a lot of the gel color because it wasn't dark enough. now the fondant crumbly........what can I do to make it stretchy again, thanks.

little bit of shortening mixed into it should do the trick.  Color will deepen overnight.

added the shortening but its still not coming together!

Maybe this will help. I haven't tried.

http://cakesistersmoncton.weebly.com/1/post/2013/02/a-fondant-break-thru-that-wont-break-your-fondant.html

from now on try melting wilton candy melts and mixing them in. Then you will not have to use as much color. Meghan is right...the color will deepen overnight so don't try to get your exact shade you want. Too much gel will destroy it.