I purchased a painting from an artist but I don't like it. Could I return it and ask her to paint another one?

Depends entirely on the ego of the artist. You can always note that you were expecting more vivid colors and see what the response is. They may be more than happy to exchange - or they may think you're rude and do it anyway. Do you care more about what an artist thinks of a person they won't remember next week or do you care more about the art you could have on your wall for years that you're not happy with?

If you are not happy with it, return it. The fact that there is a restocking fee tells you that these things happen and the artist is well aware of this. Try to work out an exchange for another painting and you may not have to pay the fee. If the other painting is more expensive insist that the fee be waved. Don't worry about offending the artist and don't let this become a factor in negotiating a new deal. If you don't like anything else the artist has in stock don't waste your money, pay the fee and look for another artist that has want you like.

artists are very sensitive. can u recall looking at the reproduction before buying it? it is apparent your complaint about the colors is an after-thought. are u sure u will like the the newly painted one?