BCGControlBar Pro for MFC
void CBCGPProp::SetState ( LPCTSTR  lpszToolTip,
TCHAR  cIndicator = _T('!'),
COLORREF  clrState = RGB(255, 0, 0),
BOOL  bDrawBorder = TRUE,
int  nStateWidth = 0 

Sets a property custom state.

lpszToolTipThe state tool tip text.
cIndicatorThe character of indicator that will be drawn near the property name. Default is '!'
clrStateThe color of the state indicator. Default is RGB(255, 0, 0) (Red)
bDrawBorderSpecifies whether to draw border around the property. The color of border is specified by clrState parameter.
nStateWidthSpecifies width of the state box. Pass 0 to this parameter if you wish to draw a default-size (square) box. Usualy, you need to use a custom width value if you override OnDrawStateIndicator() method.

Call this function to modify a property state. You can use it in order to indicate incorrect property value or some other state.

Call CleanState() method to clean-up the property state