The acrylic paint is first mixed with small amounts of the various color concentrates until the desired color tone is obtained. Then simply apply the paint to the water surface with a brush. By the way: The water base color set is ideally applicable in combination with the model water products from ZITERDES Waterdrops and ZITERDES 2K water gel. Dark color stands for deep waters, brighter shades for shallower waters. In the case of a lake, we recommend that you darken the middle and brighten the edges lighter.