I saw an idea for a color matching game on Pinterest (searching through many many unattributed pins on that site led me to find this post which seems original although not the one I saw). I made a set for each child and brought them along on our trip overseas to have as a surprise activity.
It was very easy to make – I got some paint samples from my friendly local hardware store and a handful of wooden clothespins from Dollar Tree. I cut each paint sample in half and used one half as the base of the match and cut circles from the other half. I happen to have a 3/4″ circle punch which made this easy; without the punch I would have just cut rectangles the same width as the clothespins. Then I glued the circles to the end of the clothespins and they were ready to go.
I made this set for my 3-year-old. For my 5-year-old I used paint chips that had more colors so she would have to work harder to match the gradients. Both kids enjoyed this activity and it was light enough to take on the airplane, and they’ve played with them occasionally afterwards.