My only suggestion is to make the quilts different enough that it is easy to see whose is whose. Of course, that may not matter really, but I can see a toddler carrying around her own quilt and being able to identify it easily because it was mainly one color. Or a busy mom trying to figure out which quilt goes to which baby.
And then again, it probably wouldn't matter if they get mixed up....all for one and one for all, and all that. I suspect triplets share everything, at least for a long time.
Dina