The link to the options tab icon in tabmail.css is no more 100% correct. Toolkit also removed the color in the SVG file. This defaults to black. The pro of this is, we can now set the color dynamically.
Created attachment 8888828 [details] [diff] [review] optionsTabIcon.patch There is now no need to set a target in the link. And the icon gets now the currentColor, that means the tab text color. Jörg, when you test it, enable drawintlebar and choose a accent color which makes the text white. Then you see the color effect when you select/unselect the options tab. Without drawintitlebar you see, when the window is inactive a lighter tab text. This isn't possible to the icon because the SVG icon doesn't check the -moz-opacity-property. I wrote this, so you don't need to ask why it isn't the same then. ;-)
For the record. The icon is changing it's color to be always good visible also on dark backgrounds.
Comment on attachment 8888828 [details] [diff] [review] optionsTabIcon.patch Works perfectly. All questions I would have asked already answered. Nice! Just one comment: I find that accent colour pretty ugly and it gets worse when it's dark. All looks like a mobile phone now :-(
It's a matter of taste. The Ubuntu default theme has a dark toolbar where we have the tabs. You could also use a LW-theme to give it an other background.
Pushed by firstname.lastname@example.org: https://hg.mozilla.org/comm-central/rev/ce177a27be84 Fix color of icon in Options tab. r=jorgk