We hosted a play-date for 10 toddlers ranging from age 2 to 4 (plus younger siblings) from my daughter's play-group.
As the guests walked in, they were asked to "color our walls" (which were covered w/ easel paper). My daughter (age 2.5) helped make the "paint splatter" crayons by peeling and breaking crayons, which we melted into the splatter shape.
Guests were then given little cups with beads and pipe-cleaners to make bracelets.
Then we did a salad-spinner art activity, which the kids LOVED. They got to place the paper in the spinner, pour as much paint as they wanted, and spin it to their heart's content!
While they waited for a turn at the spinner, the kids painted aluminum foil trays. The trays were great because the kids could wipe off the paint and use them again and again.
Food: Rice Krispy "paintbrushes", "R-O-Y-G-B-I-V" fruit platter, colorful cake-pops, "paint blot" cupcakes, "paint spill" jello cups, "creative" juices, strawberry/cream cheese sandwiches, colorful pasta and salad