The default colouring of the collections tabs (added for issue #25) makes them a bit hard to distinguish. It would be nice to colour the current tab or somehow make it clearer. I like the look in Thunderbird 115 (Supernova) with a blue stripe on the current tab, and the others being in a darker grey.

The default colouring of the collections tabs (added for issue #25) makes them a bit hard to distinguish. It would be nice to colour the current tab or somehow make it clearer. I like the look in Thunderbird 115 (Supernova) with a blue stripe on the current tab, and the others being in a darker grey.
