Decide which color you'd like the sand to be and squeeze food coloring into the cup of water.
Pour half of the sand into a bowl and slowly add the colored water. Mix well with a wooden spoon and slowly add in the rest of the sand. Let dry overnight. If the sand is too dry, add more water.
Once your colored sand is dry, pour it into glass vases. The sand should be about 5 inches high.
Place candles on top of the sand.
Group the glass vases together for best effect.