While the typical food coloring relies on synthetic dyes like ... Spinach Powder Water Test: Once added to water, this solution was dark, hunter green, fully opaque, and homogenous.

In a small plastic cup, add 2 drops of green food coloring. Use a cotton swab to soak up the food coloring into one end of the swab. Touch the end of the swab to the center of a coffee filter to make ...