i have a friend that wants a cake done in pink and lime green but i caint seem to find that certain color in the icing gels.do i need to mix colors together.please help!!!

Which brand of "icing gels" are you using?

Try mixing together Lemon Yellow and Leaf Green (Wilton brands)

or

Americolor's Electric Green or Avocado Green with yellow work well too.

Thanks!!!!

The cake in the link below was made by using Antonia74's suggestion of Wilton leaf green and a small amount of lemon yellow. The pink is CK brand "Cherry Pink."
HTH!
http://www.cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1199828

Start out w/ a good yellow & slowly add the green. I did the mistake of starting out w/ green & adding yellow for my pink/green cake. I had the time of my life, but all that matters is the girl LOVED it (I used leaf green, a tad of moss, lemon & golden yellow---yes I know a lot, but it wasn't as dark as the pic she sent that's why the mg & gy)