BCGControlBar Pro for MFC
void CBCGPColorIndicatorImpl::SetColor ( const CBCGPColor color,
const CBCGPColor clrGradient = CBCGPColor(),
const CBCGPColor clrBorder = CBCGPColor(),
BOOL  bRedraw = FALSE 

Modifies indicator color.

colorfill brush
clrGradientfill gradient brush, if default, indicator will be drawn using solid color
clrBorderborder brush, if default, the border color will be calculated automatically.
bRedrawTRUE - redraw indicator