Why not do this on sand? Snowy day activity: Fill bottles with food coloring and water; go outside and paint. I did this with the kids but with spray bottles. The squeeze bottles would be much better. Going to use those next time. So much fun!
Cool science experiment for kids! Rainbow Roses Get white of cream colored long stem roses. (Carnations work well too). Cut the stem according to the picture, you will then place 4 glasses of food color dyed water together. Put one piece of stem per color and allow the flower to soak up different colors.