There certainly are -- I haven't grown any of the named strains myself, but they are everywhere in evidence come spring (often, but not always, in mixtures with other solid colors). However, you can go to the link below for a listing of some contemporary strains of pansies, including some that are indeed a true, solid blue. Look especially for the ones with "True Blue" in their name, as this is their main selling point.

Here is a link that might be useful: Pansy series/strains