In the past I have used visuals (PowerPoint and color wheel) to show different color relationships. But I decided to start this year out by letting the kids just play with the primary colors and discover how many different color variations they could find.
To begin the activity, I set a few ground rules for behavior expectations (with an emphasis on cleanup behaviors). I gave a quick demonstration on how to use the trays and then laid out the procedures for acquiring materials and properly cleaning up at the end of class. Students were given a paint brush, tray, paper, water, and plenty of paper towel sheets. We used liquid tempera and I instructed the kids to put about 3-4 drops on three different sections on their tray (using only blue, yellow, and red). From there, the students used the remaining sections on the trays for mixing their colors. They were also asked to record their color discoveries on their blank paper.
As this was an exploration activity, the students could make "puddles" or "pictures." Most made puddles. All had fun.
Cleanup was a bit of a challenge. I have assigned specific tasks for table leaders (table leaders rotate each week) and then all student are responsible for the cleanup of their own tray and work area (including putting their work on the drying rack). Students wiped off the paint from the trays, and then used a spray bottle to add a bit of water and removed any remaining paint residue. Cleanup took about 8 minutes.
We have some basic cleanup rules: no wandering, clean your area and then help your table mates, put all materials back where they belong, sit at your table when you've finished your responsibilities. Only table leaders are allowed at the sink (I only have one sink). That rule has saved on many a log jam. I let students spray their hands with the sprayers and use the towels for drying if they insist on hand washing. I always emphasize personal responsibility in my classroom. The kids know that if I end up cleaning up their messes, we'll probably not repeat such messy activities. So far, so good.
Next week I plan on adding both white and black to the color selections and have the students explore tints and shades.