Colored ice cubes are a great way to spice up water play in the tub or in the kitchen (I like to pull out bowls and spoons with some water for the kids while I cook). I think Miss J actually thought she was cooking. As soon as her ice cube melted, she would ask for another one to stir around in the water. This can also be a great way to teach mixing colors. For cleaner play, put two different colored ice cubes in a ziploc bag and let your child swish them around and melt the colors together.
These are also fun to throw in the wading pool! See who can find the most blue ice cubes, etc.
I don't think I need to give directions but just in case...
Mix water and food coloring together. Pour into an ice cube tray, being careful not to mix different colors. Freeze. Enjoy!