I have a website with two conflicting page styles
Currently for any new page I have to manualy change the background and some elements

The landing pages all have a white area at top as a background to the videos, and the other information pages are darker grey.

So the H1 text, for example is black for the white background, but on dark pages I need it to automatically change the H1 to white.

Is there an easy way? I tried the Automatic colour, but that doesnt do it.