Do you have a Twister Game sitting around your house?
Why not get it out and play it outdoors and have some messy fun!
I used a full container of shaving cream and about 10 drops of each color of food coloring to make the shaving cream dots.
We invited the neighbor girl to come over and join my kids (trade off was she had a large kiddie pool out that the kids could rinse off in afterwards, otherwise I had our Octopus Kids sprinkler ball ready for them to use).
The kids couldn't resist getting messy and after they finished playing. Yes, it took longer for me to gather supplies and set everything up than the actually made it through playing but with a 5 year old boy who wanted to get messy I knew that was par for the course.