There are many possibilities and everyone is different. However I can state that one interesting viewing experience I can get on my current OLED phone at night is to put it in greyscale mode plus the blue light filter set to the warmer end of things and the brightness dimmed a bit to make things look flatter. Gives white pages a nice sepia tone and all elements are displayed as black or grey.
Edit: It's not great form to change both the thread title AND the original post's body text to make an existing thread into a completely different one. This makes my response look out of context to new viewers.