Why wouldn't French last as long ?
If you use Gelish properly, it doesn't matter what color you use, you will get the same long lasting effect. I did myself a french with a pink tip and it's just the same as white.
I use Sheek White and Simple Sheer. It's a really clear pink just gives a hint of shine, and when the client's nails grow, the regrowth of the nails isn't noticeable.