We paint with all sorts of things outside .... cannot hurt to try ~ it would provide a new sensory experience to it of the smell and potential taste .... but honestly you only need 1-2 drops of food coloring in the whole bottle for it to color the snow or ice as they spray it and unless they are spraying themselves on purpose it should not be straining .... little pink and white snowsuit girl always washed up each Monday like new when they brought back her snowsuit after a week of outside fun