I'll throw my 2 cents in:
The key to a successful scrap quilt (or any quilt, really) has less to do with color than with VALUE. Value is the key.
If you want to make, let's say, a purple quilt, if you choose all dark purples, even with a nice selection of textures and prints, you're going to get a "blob" of a quilt. The eye doesn't really travel over the whole quilt because there's nothing different about the different sections. No variations.
Now, if that's what you want, and it's for your yellow bedroom, then it will definitely stand out against the walls.
However, if you want some definition in a quilt, imagine now a collection of dark purple fabrics along with a variety of lilac or lighter colored purple fabrics. Again, the color is actually secondary.
I've seen scrap quilts made out of the ugliest fabrics - all colors - but the value placement was so brilliant you didn't really notice.
So my suggestion would be to learn a bit more about value, and how that can make or break or a quilt.
"Spectacular Scraps: A Simple Approach to Stunning Quilts" was a great book by Judy Hoosworth. Much better than some of the more recent ones out there.
Just my 2 cents. And NAYY.
If you want to see a great example of the value of value, there is a blog called
http://exuberantcolor.blogspot.com/. She (Wanda?) only works with Kaffe Fasset & the like fabrics. But if you look through her quilts, even though she used blocks as simple as Rail Fence, her quilts are bursting with vibrancy because of her value placement.
Also,
scrapquilts.com has some free patterns and additional inspiration and directions.
Good luck.
-MTS