How can I change options in Firefox using webextension. I would like to change some items from about:config like browser.display.use_system_colors
You can only modify settings explicitly exposed by the API. I don’t think there currently is an API related to using system colors nor do I know of a proposal to make that pref accessible. But if there is a compelling reason to be able to modify it, I’m sure a proposal for an API would not be rejected.
The reason why I need to change it is because I often change that settings. I often need to switch between default system colors and website colors. Using Color that Site! extension I have applied black scheme to some web sites. I have also create an extension which enables me to inject my own style to any webpage. But when I have default style active, the color changes (background and text) are not visible. So I have often to switch this manually. This is boring and slow. So I need to create icon which will enable to toggle it or hotkey to activate the toggle.
There are these two options in Content settings:
“Use system colors”: checked
"Override the colors specified by the page with my selections above": always
This applied default colors to sites. In my system I have set colors which does not make my eyes hurt (no white background).
To enable the css styles injection I need to switch it to:
“Use system colors”: off
"Override the colors specified by the page with my selections above": never
It is 8 clicks total! Now imagine that you need to do it often. That is crazy!
I am sure to make suggestion. I am sure I am not the only one who minds this. Especially users who have set black theme in their OS and want to apply it to webpage. But not all webpages looks good using default styles. Some looks good in black background some in system colors.