I not only agree with watermom, but would like you to let us know if you notice ANY fading from swimsuits at all. An FC of 10 with a CYA of 30-50 should technically be equivalent (in disinfecting chlorine) to an FC of 0.2-0.4 with no CYA so I doubt that your swimsuit will fade at all. Of course, I could be wrong so it's better to play it safe as watermom suggests.

My wife's swimsuits have the rubber wear out before they fade, but they only seem to do this during the winter when she uses an indoor pool (at a local community center) where they almost certainly do not use CYA (and probably have FC > 2). Neither she nor I have ever had a problem during the summer with our own pool even with an FC of 5 and CYA of 15 which should be similar to your FC of 10 with CYA of 30.

Richard