I picked the two main colors based on what my son told me she liked (peach and turquoise). Then I picked an extra color (the purples and purply-maroons) to make it a bit more dynamic. I thought it really needed more than two colors.
Don't let choosing colors intimidate you. Go with what you like the best, and if you have to add another color or two, go with the colors you like next. I've found that most colors will compliment each other in a quilt. You will simply change the "tone" of the quilt by what you choose to place in the same quilt.
I was intimidated by colors too when I first began, and then I read a wonderful book called Color Magic for Quilters by Ann Seely & Joyce Stewart. It really opened my eyes to all the possibilities available for mixing and blending colors! I would recommend this book highly.
Thank you so much for your nice comments. :)