if you call cnd at leeds, not sure about the number, they will be able to let you know the top ten most popular colours. Perhaps you could email samantha sweet and she will definately have the number for leeds,
Essie is known mostly for their sheer "frenchie" kind of colors. Do a search on their site, and they can give you their top 20. I know some off hand, because I use Essie A LOT.
Blanc, Waltz, Ballet Slipper, Madamoiselle, Sheer Bliss, Future's French, Like Linen, Adore-A-Ball, Marshmallow, Allure, East Hampton Cottage......to name a few.
I use Essie's Marshmallow and Allure for a soft, natural French manicure with lovely results. Blanc is Essie's much brigher white, but for some reason I can never get on with doing a bright white French manicure no matter what product I use.
If a client has discoloured nails (from wearing dark polish without a basecoat) and wants a French manicure I use Ballet Slippers for the pink base. It disguises the yellow without completely covering up the white.