Any way for more accessibility for editing colors?

I'm using Origin theme for my website, on the theme editor recoloring is good enough but there are some options missing such as:

 

1. Recoloring inside the blocks.

2. Recoloring block titles.

 

I don't want to mess with the FTP, did anyone found the exact source code to recolor inside blocks at least? When I try to convert it to dark theme and switch entire background black or dark gray inside the blocks remain white and it looks awful.