ya fiction-girl is selected to compete for the crown, painter makes her ugly and she runs away PLEASE help!!!

I read this book a while ago maybe five years. I never got to finish it though and it has been bugging me ever since. It is a relatively thin book and I think the cover may have had a red/orange sunset.
So it started with a really pretty girl being selected to compete for the prince's hand in marriage. A major thing that I remember was when the lady got to the palace, a painter was sent to her room to get a painting of her to show to the prince to eliminate the unpretty girls. The painter was collecting bribes and painting the rest of the ugly people pretty. The girl, however, wasn't having it and she didn't pay anything so the painter painted are ugly. She was going to be sent home in a carriage but she jumped out and she hid in the river until the guards left.
I hope this is enough thank you so so so much to anyone who helps!

The business about the painting and the bribes sounds like Imperial Lady by Andre Norton and Susan Shwartz - it's set in Han China.

Silver Snow can't pay a bribe even if she were willing, though; all she has are a pair of heirloom suits of jade burial armor earmarked as gifts for the emperor.

They don't send her back to her father, though; she's kept in the harem but never sees the emperor. However, eventually to seal a treaty, they need to pick one of the ladies to adopt into the imperial family and send away as a bride to a tribe out on the steppes, and the emperor remembers just the person on the list because of the portrait...

I should add that this is based on a legendary/historical incident, so even if Imperial Lady isn't the specific book, it might well be a different retelling of the same legend that you're thinking of. The jumping-in-the-river bit sounds like it might be taken from a variation of the older story that Imperial Lady is based on.

The name 'Silver Snow' is an English translation of a name also given as Chao Chun.