Open WB config, Colours tab, uncheck I want to adjust the colour of my skin, apply changes.

Best way to change for just one skin, From drop down that says, Change clours for all skins, select Create new, next dialog click create new button, I just give it a colour name as this is going to create a new sub for the skin, click create, it will now be selected in next dialog window, click close. Then adjust the colour to what you want and apply changes. This will save it as a sub style for the base skin.