A few years ago I found some Paper Mache eggs at a craft store, colored them with food coloring and water. Then cut up some toilet paper rolls and painted them the same way. It was my little DIY Color matching activity for D.
This year stores have cartons of plastic eggs to dye, and they include paper stands. We colored these with marker and opted to use TP rolls because they're sturdier for little Lulu.
The picture below shows the inside of the tray. The circles were made with marker for an additional color matching option.
LuLu, at 12 months, you say "yeyeh" (yellow) and "bwuah" (blue). You identify the two and like to point them out to us as you see them, from time to time. You learned them through play. You've been given opportunities to play based off your interests, and we simply talk you through what you're doing (to teach).
It was no surprise you figured out a way to stack these right away as you love to stack in our block area.
We demonstrate how to match colors, but you choose to explore your own way. At such a young age, you're only interested in learning when we allow you to play freely.
Teaching example: "You have the green egg. You're matching it to the green stand. Now you're putting it on the blue stand. Look -- a green egg on a blue stand. Now you're stacking the eggs ..." Just talking (teaching) while you play.
My favorite part is playing along:)
Other ideas
Number recognition/matching:
number the eggs and number the bottom of the cartons and/or TP holders.
Shape recognition/matching:
Draw shapes on the eggs and bottom of the carton and/or on the TP holders.