Each layout will have different dimensions for the different div elements so will need a separate css style sheet. if they al used the same CSS, they would all be the same layout.
You could create a new style sheet named myStyles.css and use that to overide text color and size. as long as it is the last css file attached to each page, and all of the pages use divs with the same name, the mystyles can be used to override the text color or size on all of the pages that use it.