Multiple ideas:
- Paint the same color as the walls
- Take the doors off and put up a curtain that coordinates with the bed linens
- Assuming they are real wood: If you're okay with experimentation, buy some stain and some sand paper (if there is a poly coated finish on the doors) and try to even out the color a little.
- If you're looking to get all artsy fartsy and want to make some kind of inlaid wood design, you can buy rolls of oak veneer (for edging tables and stuff) for a a decent price and make some kind of design, like herringbone or something. Most that I've seen have a heat activated glue that should work with a regular iron. Then you can stain it to match the woodwork.