Can't register style to dev-tools

Question

I created a test extension, to change a few things and maybe add some features to Firefox built-in devtools.

I set up a basic extension, with content css and the usual files, and chrome.manifest:

content devtooltweaks   content/
style chrome://browser/content/devtools/framework/toolbox.xul chrome://devtooltweaks/content/devToolStyle.css

Although I can go to "chrome://devtooltweaks/content/devToolStyle.css" and see that file exists in the browser, DOM inspector doesn't show the style applying, I can't see the stylesheet listed either. It's been a long time since I did extension development, is there a step I'm missing here? Or is it not permitted to change the built in dev tools, similar to how it's not permitted in Chrome?

Answer 1

It looks like the style is imported, but not shown as a stylesheet in the DOM Inspector, I also may not have been using firefox -purgecaches. It's working now.