I use Fiberguard and I LOVE IT! It retains the tensile strength and elasticity of the hair, and it is excellent for color treated hair. My hairdresser uses Affirm and Fiberguard on my hair, depending on whether I have used color recently or not. Both relaxers work great. I used to use optimum before I switched to a hairdresser who used Affirm. That was 7 years ago, and I will not use any other relaxers. I urge you to try Affirm or Fiberguard. Check out their web site: www.avlon.com.
That being said, you should find out what works for you. 