Where Small Things Will Soon Be Sorted

Along with chauffering babies to school and gymnastics, straightening up a living room that immediately got trashed again, hanging up what seemed like five gazillion loads of laundry on the line, buying $40 worth of gasoline for the minivan, making patterns for jammie pants for me and my babies because I want mitchy-matchies with the monkeys, but I also plan to make them the Story Time Pajamas from Oliver + S this weekend), and cooking a dinner that once again nobody ate but me (and yet, if I DON'T make dinner, that's apparently a problem as well), the girls and I spent most of the morning out in the front yard painting on egg cartons:
I'm not quite ready to deal yet with shopping from within an ethic that only buys from egg farmers who only buy from hatcheries who don't deal cruelly with male chicks--have to find the time to do the research on that one--but we do buy cage-free and organic, and local when we can, and the benefit of that is that the eggs always come in these AWESOME recycled-cardboard cartons. I save every single one, and the girls and I went to town on maybe a dozen this morning. I actually brought them out to paint myself while the girls painted on big paper, but the girls were compelled, COMPELLED, to paint cartons, as well, and I'm not sure why, but they had themselves a ball.

We have a LOT of paint, good thing:
In the end, I only managed to rescue two egg cartons for my own painting, but through my own paint mixing and the girls' far more creative paint mixing, I ended up with a fine bevy of colors for them:
Chasing Cheerios uses these for collecting nature colors, but I find so much appeal in the smallness of the containers within the carton that I'm trying to think of something inherently small for the girls to collect and sort into the appropriately-colored container.
Buttons, perhaps?