Add-ons • Can a light theme be edited to split background color of menu bar and nav bar into two?

Not sure if this post should go in add-ons, but it seems the best fit.

When creating a light theme using Theme Builder, and backing up the theme, it saves it as a .json file. When opening one of my saved light themes in a text editor this is what I see:

CODE:

{ "id": "LT-#f5b87a-#000000", "name": "Rust.Orange: #F5B87A/#000000", "headerURL": "resource://chrome/toolkit/skin/classic/global/scrollbar/slider.gif", "footerURL": "resource://chrome/toolkit/skin/classic/global/scrollbar/slider.gif", "textcolor": "#000000", "accentcolor": "#F5B87A"}

What is listed as "accentcolor" is the background color, on both the menu bar and the nav bar. Is there a way to edit this line into two lines, one for the background color of the menu bar, and another line for the nav bar?