Support browserAction.setBadgeTextColor()

[AidanWelch]

Firefox has supported setBadgeTextColor() since 2018, but no other browsers currently support it. Standardizing a relatively minor function that would improve the customization of extension badges seems beneficial.

[carlosjeurissen]

In addition to browserAction.setBadgeTextColor, Firefox also implemented browserAction.getBadgeTextColor. And for compatibility with manifest v3, action.setBadgeTextColor and action.getBadgeTextColor should be considered.

Some additional background can be found in the bugzilla issue report:
https://bugzilla.mozilla.org/show_bug.cgi?id=1424620

I suggest to first discuss how the foreground color is determined by browsers, see if we can find alignment on this field as well.

[xeenon]

We should keep dark mode in mind here. We likely would need to let the caller set a color for each mode so it can look right if/when the user switches their UI between light and dark modes.

[hanguokai]

I would like to know what is the default BadgeTextColor and BadgeBackgroundColor in different browsers (if developers don't set them).

On Chrome, the default is White/Blue. And Edge's was the same as Chrome in the past. But recently Edge changed to White/Red.

[hanguokai]

Here is a related chromium bug about badge's color contrast. The problem is that, in some cases, the badge text color chosen by the browser is unreadable, especially the badge is very small. Maybe some color experts can help solve it.

[dotproto]

Chrome is open to exposing action.setBadgeTextColor() but don't have immediate plans to do so. We will be using crbug.com/1337783 to track this feature request.

[carlosjeurissen]

There is further progress on this on https://crbug.com/1363445

[hanguokai]

Close this issue. Because Chrome has implemented action.setBadgeTextColor() and action.getBadgeTextColor(). They are available since Chrome 110.