Last weekend I was in Pittsburgh at a horse show and I came across these breeches from Equine Couture. They are made out of a material similar to Coolmax so they keep you cool. They are very thin and tight fitting but very cute. These were a raspberry pink color. They came in other colors - a deep blue, white and tan but these were by far the cutest. They were very comfortable too and at a good price point, $89. I sized up one size as my normal size was very tight and I wanted them a little loser.
The back side is equally cute.
They also come in a full seat model. If you are in the market for summer breeches, good price point, fun colors, that will keep you cool all summer, then you might want to try these. You can shop them here.