I "matted" the various sized pieces in red, sage green, light blue and yellow. Now I'm adding a black frame around each. I've been imagining this like a photo wall where the matching frames are what pull together all the pictures.
The color mat squares are of various sizes of 6-7". I have 2 options now. 1) use the same width black frame on every square so the finished size range is 11-14" OR 2) add frames that would result in a finished block size of 12ish inches for all the blocks.
My other decision is on how to combine the blocks. I had originally imagined red sashing. Now I'm thinking that might compete with the mats. White seems too stark. Grey seems muddy compared to the primary colors. A black print would lose the frame detail. Maybe a brighter blue, in a print. But of course, I don't have any of that in the stash. Hmmm. More ponderation.