It’s a bit tricky:
1. Go to rasite/css/menu/mega.css
This is one part of the css file that controls your menu colors/layout.
2. Also go to rasite/css/colors/yourcurrentcolor.css
There you will also see mega menu rules.
– Because it was getting way too much for me and because I only use one of the many color options, to simplify things, I deleted the mega menu rules in the yourcurrentcolor.css, replaced the mega.css with that of of ja_purity II and focused on editing the rules in this file. It was way easier:))
– You might want to do the same if you have good css experience. Before making any changes backup your files or rename them. Never work in production either:)).
3. Your current mega menu images are in images/yourcurrentcolor/
Hope that helps:)