Not unreasonable. Paint is a great, relatively inexpensive fix. If the flooring/carpeting idea doesn't go over well, perhaps they would consider a large area rug to cover most of the green carpet--perhaps something that incorporates lots of brown and some green, or even one of those sisal mats? Do your homework, though--investigate prices for paint, flooring, and rugs before you approach your parents about this project. Do you have any money you can contribute to the cause? Are there any jobs or projects around the house you can do to earn new flooring? Go to your folks with options. They will surely appreciate the fact that you checked prices on paint and flooring (get prices from three different sources) ahead of time, and that you are willing to do as much of the work yourself as possible, plus do things at home to help pay for it. Good luck!

No reason not to ask. But you should offer to do most of the work, and or express an intrest in learning how to do it. A high quality gallon of paint ranges $25 to$30, not outragous.... you might be able to chip in on some of the expenses if you have some cash or an allowance

It's fine to ask to repaint. Paint is cheap. Changing to hardwood floor would be expensive, though. You can ask for that too, but I wouldn't expect them to say yes.

Back in 2011 my parents let me redecorate my room, and I messed up terribly. I wanted sort of an outdoor theme, so I painted the lower halves of my walls a dark green to look like grass, and the top half light blue to look like the sky. Then I had a green carpet put in that doesn't match the green on the walls. On the back wall behind mine and my little sister's bed I have a poorly painted willow tree. I've grown out of this little-girlish layout and I really want to change it. I want light brown walls with maybe a hardwood floor or a brown carpet. Do you think it would be unreasonable or bratty to ask my parents if I can redecorate? Should I wait a few years and then ask?