Use a medium-sized brush to whitewash the plaque, using a 1:1 mix of Snow White and water.
Put a dab of all colors on the palette or paper plate. Use a medium flat brush (3/4" is ideal) that's been saturated in water and begin wiith Royal Fuchsia as the top color of the rainbow. (See photo.) Rinse the brush; saturate again; and continue on the next color, Coral Blush. (Be sure to overlap this color with the Royal Fuchsia.) Continue this same process with Hauser Light Green and Shoreline to complete the rainbow.