BCGControlBar Pro for MFC
void CBCGPColorMenuButton::EnableAutomaticButton ( LPCTSTR  lpszLabel,
COLORREF  colorAutomatic,
BOOL  bEnable = TRUE 

Enables the color menu button to be an automatic button

According to bEnable parameter turns this button to automatic or regular.

lpszLabelSpecifies a button's text that will be displayed when the button becomes automatic
colorAutomaticSpecifies a new automatic color
bEnableSpecifies whether the button is automatic or not