Hi Terry,
Thank you for evaluating Syncfusion products.
I am able to reproduce the issue that the custom colors are applied once the form is focused. This issue can be avoided by setting the customer color of the MainForm in the ColorPickerUI control's picked event. Please refer to the sample given below:
http://websamples.syncfusion.com/samples/Tools.Windows/F79252/main.htmPlease let me know if any concerns.
Regards,
Fathima