EM Client Windows Colors

I have adjust in W10 the windowscolor so that the Main Winows top Beam has a other Color then the rest. Way: I is better to pickup a Windows to adjust on the scree. Is work fine in any Application except Emclient. In the Emclient there is no effect. The first and second Beam has always the same Color depending on the Style white/wite or blue/bule. Why? See example


Can you please include a screenshot of the issue? Thank you.