“Where can I find colorful bedspreads?” isn’t a question?
I can’t answer for samclem, but it does seem like a question more given to answers based on opinion than fact.
Come back and tell us more of what you’re looking for in a bedspread! Now I’m obsessed with finding the right one.
Darnation!
I finally found some very pretty ones, I was all excited…
Then I measured my bed. I’m a twin. All but one were kings. Back to the drawing board.
(Maybe I can buy a king-size and cut in in half so I have one for later?)
The first one could be OK for trimming the width, but for the second one, the pattern would be ruined if it’s trimmed.
This place has twin-sized cotton quilts in bright colors:
http://www.linensource.com/default.aspx?page=products&categoryid=159&cmd=All&sortby=0
No offense taken. I didn’t like it, either, but I didn’t have a lot to go on, given your description. 
The difference between a comforter and a bedspread is this: A comforter is more like a quilt. It has a puffy fill layer between two layers of fabric. They are often reversible, with different fabrics on the outside layers. They generally reach to the bottom of the box spring and are often used with a dust ruffle. A bedspread is usually a single piece of fabric and reaches to the floor.
It might be worth a shot to contact the eBay sellers and ask them if they have similar items in twin. FWIW, my sister has a sari patchwork bedspread she got on eBay. It is beautiful, but not very practical if you like to stretch out on your made bed to read or nap or whatever. The patches with brocaded silk are very scratchy.
Okay, I have chosen The Bedspread.
I don’t know how long the link will stay up now that I bought it, so see it while you can: http://cgi.ebay.com/Tie-Dye-Bedspread,-Twin_W0QQitemZ230365519713QQcmdZViewItem