|+24||ColourPicker Choice Flags|
|+28||ColourPicker Colour Descriptor|
This message is sent by ColourPicker to inform the task that the ‘OK’ button has been clicked.
This message may or may not be followed by a Message_ColourPickerCloseDialogRequest.
The ColourPicker handle is returned when creating the ColourPicker window calling ColourPicker_OpenDialogue?.