The Brush window

This window displays loaded brushes.
Select one by clicking on it, the brush will follow you mouse on the main (and zoom) window.
(Brushes are 32 bits).
The BrushEditor window

This window is usefull to create smooth round brushes.
You can choose the size of the brush and the smooth value.
Click "ADD" to add the current brush in you brush list.
To specify colors, use drag&drop. The "alpha only" checkbox restrict your brush to only one color.