This policy setting controls the default color for window frames when the user does not specify a color. If you enable this ...

This policy setting controls the default color for window frames when the user does not specify a color. 

If you enable this policy setting and specify a default color, this color is used in glass window frames, if the user does not specify a color. 

If you disable or do not configure this policy setting, the default internal color is used, if the user does not specify a color. 

Note: This policy setting can be used in conjunction with the "Prevent color changes of window frames" setting, to enforce a specific color for window frames that cannot be changed by users.