Watercolor Wash Brushes
I did a sample of the Brush Swatches. The brush color depends on both the foreground and the background colors selected, so the more bright/saturated the background color is, the more colored the brush is, but if you want to keep it looking like one color with water added with pressure, you can keep your background color white.
Here are two gifs I used the watercolor brushes to color the following pieces
Here are two more pieces, that I used the brushes on:
Watercolor
Ink Wash
Brush