In the Tower

I wanted to practice painting scenes and background instead of just character illustrations. This is a scene from Game of Thrones (book version) when Brandon stumbled onto an intimate session better Cersei and Jaime Lannister. My biggest problem is color selection, I'm having a really hard time making it look natural. I'm pretty pleased with the skin tone but that back ground looks daunting. The more time I spend on this the more I realize that I should have started out with a proper line art instead of just adding elements as I go. Learning progress, everyday.