Hello Zohar
I can suggest two ways :
1. Set the sPanel.SkinData.SkinSection property to 'GROUPBOX' and sPanel.SkinData.CustomColor to True. You will be able to change sPanel.Color property as you want in this case.
2. Make any amount of new SkinSections in used skin, you can make any different kinds for different panels and use them later after defining of SkinData.SkinSection property.