what you ask can be easily made with conditional formatting of 2 text objects but the best result is obtained with square tabs.
The first text object must have a black text reproducing the name of the tab and has the same dimentions of the head-tab.
The second object must have a space and text with the same color of the object and has the same dimentions of the body-tab.
Both objects are over the tab to be coloured ( or not ) and both have conditional formatting by a calc like this:
where the radio button have a list of only a value ( 1 ) attached.
If you have difficulties to reach the result, I can send you an example file.