Thank you for your very nice message. :-)
This theme is in its final form and will always be accessible, I assure you.

If possible accuracy? I don't understand:
"Would also love to see another theme exactly the same except all black right across the top"

This theme is part of a collection which declines it in 10 dominant colors.
Have fun !

https://addons.mozilla.org/fr/firefox/user/13050680/