Solid Brush
The image below shows a solid white brush with opacity of 75.
The brush has been applied to a panel on top of which is the foreground text. Opacity of 75 allows the background to be visible through the panel:
Solid brush is used to define a brush with a single color:
Define_Com Class(#prim_vs.Style) Name(#Style) Backgroundbrush(#Brush)
Define_Com Class(#Prim_Vs.SolidBrush) Name(#Brush) Color(White) Opacity(75)