My cats are back! Rated 5 out of 5 stars

Thanks to all posted great ideas below,
I could see my green cats again!

Especially, thank you madmoggies (from a review of blue flavor) .

I had much trouble in installing jar. file (= recompressed folder), so madmoggies' suggestion was very helpful!

https://addons.mozilla.org/ja/firefox/addon/red-cats-blue-flavor/reviews/36654

>^..^<

This review is for a previous version of the add-on (5.5.2).  This user has a previous review of this add-on.