Can anyone help me with color choices for curtains?

The bedroom is painted blue with a darker blue carpet. There is a patio door (odd sized) that I need a new curtain for. Custom curtains are out of my budget range. I was thinking about using a Queen Size sheet, turned sideways, I think that would work. What color would you suggest, I'm having trouble finding prints and there are stripes but turning the curtain sideways would mean the stripes would be horizontal, would that look ok?

Horizontal stripes would be okay, depending on the colors you choose. Try to pick complimentary colors that you can easily match furniture to, rather than a blue which would make the room appear bland. If you do want to go for the "all blue" room look, try a really outstanding blue color that differs from the wall and carpet coloring.

Blue & white go great together, as well as blue and orange. (I'm not sure if you'd want orange curtains though) Maybe blue, red, white, and green. That sounds a little patriotic, but there are some cheap shower curtains at bed bath & beyond that I loved and could work for window curtains too. I wasn't able to find the exact one I'm talking about, but here's bed bath and beyond:

http://www.bedbathandbeyond.com/stylepage.asp?order_num=-1&RN=10&START=0&IPP=12

I used shower curtains rather than regular curtains in my room. Good luck!