Right. So we used to have a white current-app indicator against the translucent/medium gray background, but now our indicator is just the AppIcon border, and AppIcon specifies a border color of light gray, which is not very visible against the dark gray background. So I darkened the background. The other possibility of course would be to lighten the AppIcon border.

We are already doing this:

        // FIXME?
        appIcon.actor.border = 2;

(appIcon defaults to a border with of 1, but that was also too-unnoticeable in the app switcher context). But it looks like we can't just do "appIcon.actor.border_color = WHITE;" though, because AppIcon adjusts its border color each time you select or unselect it. So we'd either have to change the default AppIcon border color (probably bad because the white is a little bit too bold in the overview), or add a border-color "property" to AppIcon.

Or we could go back to using a separate actor for the indicator instead of trying to use the appIcon's border; that would probably be tricky wrt z-ordering with the pop-up menu though...

Created attachment 144078 [details] [review]
[AppSwitcher] Make the background translucent again

The default AppIcon gray border color isn't very visible against a
dark gray background, but a white border looks too bold in the Well. So
allow the caller to override the AppIcon border color, so that the Well
can use gray-on-black and the AppSwitcher can use white-on-gray. (And
then revert the AppSwitcher back to the translucent gray background.)

Comment on attachment 144078 [details] [review]
[AppSwitcher] Make the background translucent again

Patch looks good. So need to merge the nbtk-introduction branch, this should just be:

+ #altTab .appIcon {
+    border-color: white;
+ }

Attachment 144078 [details] pushed as 72dd458 - [AppSwitcher] Make the background translucent again