As for sweet peppers, I am growing the Lunchbox Pepper Mix from Johnny’s Selected Seeds.  These peppers are small snack sized.
This packet mix contains an equal amount of seeds for red, orange and yellow peppers. I am growing 4 plants but I am not quite sure yet if I will get all three colors or not – all the seeds look alike and the peppers start out as green. I wish Johnny’s would color code the seeds so I could end up with at least one of each color. If you don’t want to gamble, you can purchase separate seed packets for each color.
So far I have used the first lunchbox pepper in my salad for a splash of color! I hear that they are also great sauteed and grilled.
See my posts on Seed Ideas for Sweet Peppers and Sow and Grow Peppers.