I took 25 blocks home with me, and divided them into three groups. Those which did not measure the required 12.5" ( and I'm sorry to say, there were a few of those!), those which were 'pretty' and those which were 'bright'. The ones which were too small went into the orphans box, and here are the results of the other blocks.
Here are the 'pretty' blocks. I wondered about sashing them, but decided that it would dull their impact. I managed to find a piece of fabric for the first border which was the exact fabric of some of the pink squares, which was lucky. The border is two diferent fabrics which aren't quite the right colour, but frame it beautifully.
The 'brights' were a larger group and have made a bigger quilt. The yellow binding was DD's excellent suggestion - very in keeping with the theme!
Just hoping now that the block makers approve of the results!