i learned hwo to do html, but i dont know where to input codes in the format, i figured if i but bg color background code for exp orange somewhere in the comic format, it turn out orange...

anyway to input the code like where to put it?

also it owuld help if i know where to put a customized next button and back button :<

This is what you want

You also have to keep in mind that any styles such as color or font is contained in the style block of the custom layout. It effectively overrides anything you put in the actual code. The arrows are actually easy to find as they're DD proprietary functions.