This is a quote from an earlier post by Pat Lamar, president of the PRMA (Professional Rabbit Meat Association) about vulva color.
" Just because they are rabbits *doesn't* mean that the does will always be ready to breed! Bucks are always ready, but not the does. You can check the doe's receptiveness beforehand by checking the color of her vulva. Turn her over like you would to sex her, but take note of the color when you press down to cause the vulva to pop up. Bright pink to red to purple would generally mean that she is receptive. Creamy white to medium pink means she will most likely *not* be receptive and there would be little sense in wasting your time trying to breed her. Keep checking every couple of days until you are sure of the darker colors. "
80 degrees is hot for rabbits. Try to breed early in the morning when it's cooler.
Also try to breed them before you feed them. Just like people, they get lethargic after they eat!
Do they have enough light? They need about 16 hours a day.
How old are they, and how long since their last breeding/ kindling? If too much time passes between breedings, does often won't breed again.
What about weight? If they're overweight they won't breed and often won't conceive if they do breed.
Just keep at it. A lot of people have difficulty breeding during the hot summer months. If they still won't breed, consider culling them and getting better summer breeders.
Robin