Personally, I don’t know why anyone looking to seriously conceal a pistol would even consider such a finish. It not only looks horrible, but is just not a wise choice for deep concealment. Apparently, this unique, highly reflective finish found in their smaller P238 is popular enough for them to expand it to their other handguns. While still not officially up on their website, their P239 will now be offered with a rainbow finish. To each his own I guess.
More info here