Chemical strippers can attack the epoxy matrix that binds the carbon fiber. The only safe method to strip paint from carbon is to sand, cautiously. The dust created by sanding the paint and clearcoat will be white in color, if you cut into the carbon you will see a gray dust color. Stop sanding if you see gray, you won't compromise the integrity of the frame unless you are fairly aggressive cutting through the top layer of carbon, which is often a cosmetic layer. I am skeptical that you could strip only the white; it would be much easier to feather into the adjoining color, and re-spray it along with whatever you plan to do to the white areas.