Windows Mobile 6.5 is not even out yet, but XDA Developers have started designing custom Color Themes for the upcoming Operating System, based on early leaks turned into custom ROMs.
If you're brave enough and have a QVGA device that already runs a custom ROM with Windows Mobile 6.5 (which we don't recommend), you might try the new custom theme. Else, cross your fingers and watch the thread grow with themes (hopefully, different resolutions too) till the time you'll own a native Windows Mobile 6.5 equipped device.
For installation, download the cab file, install to Device, go to Start, Settings, Personal, Today and choose your new theme.