Please could you explain in further detail what you would like to change as Im not quite sure which property you want to alter. If you could include a screenshot, that would help me to assist you
From what I understand, you want to change the color of the selected tab in a tabbed document. If this is so, then you should change it through the Visual Style Builder. General help for the Visual Style Builder and themes can be found here. I have attached a screenshot showing how you can select the tab item in the Visual Style Builder.
If you need any further help, do not hesitate to contact me.
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