User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:56.0) Gecko/20100101 Firefox/56.0 Build ID: 20171024165158 Steps to reproduce: I have a WebExtension add-on that uses svg files for the icons. Since I want that the icons fill as "native" as possible I want that the color adapts. Actual results: This works in the sidebar header and on the customize page as Firefox seems to apply the CSS fill attribute here with the currentColor. It does not work for browser_action icons when placed next to the navbar. Expected results: Firefox should apply the CSS fill attribute with the currentColor (current text color) to browser_action icons when placed next to the navbar.

Actually, this might not be a dupe, currentColor isn't the same as context-fill. Do you have a simple example SVG icon that would demonstrate this?

I wonder if changing the behaviour of fill="currentColor" would be better than exposing fill="context-fill". currentColor is a standard keyword, while context-fill is not.

(In reply to Croydon from comment #0) > I have a WebExtension add-on that uses svg files for the icons. Since I want > that the icons fill as "native" as possible I want that the color adapts. > > This works in the sidebar header and on the customize page as Firefox seems > to apply the CSS fill attribute here with the currentColor. To help here I need to understand the structure of the "sidebar header" and "customize page", and how the icons are added to them. Can someone point me to the source of these two pages and describe how the icons are embedded? Are they referenced as a separate image file somehow? Or is the markup of the SVG inserted into these pages?

I imagine that the markup of the SVGs must be inserted into these pages if 'currentColor' is working, but then I didn't think WebExtensions were allowed to do that...

SVGs are still used as images, so they can't access the color. What that would be nice to do is somehow expose the color Firefox uses to the extensions, basically something like context-fill. I see two solutions that could be done: - Set the `color` property in the SVG image context when it is loaded to the color that Firefox is using - Set a CSS variable in that SVG image context I would suspect the second solution is better, but it would really be nice to have an alternative to context-fill that extensions can use. It's blocking things like the icons theming API that it would be nice to push forward.

(In reply to Tim Nguyen :ntim from comment #6) > SVGs are still used as images, so they can't access the color. What that > would be nice to do is somehow expose the color Firefox uses to the > extensions, basically something like context-fill. > > I see two solutions that could be done: > - Set the `color` property in the SVG image context when it is loaded to the > color that Firefox is using That's limited to a single color, and lots of our icons want two colors. > - Set a CSS variable in that SVG image context See bug 1421329. > I would suspect the second solution is better, but it would really be nice > to have an alternative to context-fill that extensions can use. It's > blocking things like the icons theming API that it would be nice to push > forward. Sounds like this is essentially a dupe of bug 1421329 then. Incidentally, where can I find info on the theming API?