diamondearringsfaq.com

The normal color and clarity of a set of diamond earrings are round and clear. They are not suppose to be assorted colors; blue, yellow, red,or gold.

Thats a tough question. Average is definitely the white diamond, most people dont actually go for others. It really does not matter what the diamond is in earring, necklace or even ring its the carat and clarity that counts. Clarity is really if the diamond has impurities, strangle enough a diamond must have impurities to have any other color but white. So definitely carat which is the weight and the clarity - less impurities is what counts. As far as color - white is first, you can look on this poll and cast your vote there too on the most popular diamond color

For diamond stud earrings, the average color runs H - J, and clarity SI1 or 2 to I2… Clarity is less important in earrings then in a ring, and why would a jeweler waste high color stones on earrings?
If you want nicer, you can ask your jeweler to find or make them - bear in mind that it will cost you more then the average pair, however.