THIS is exactly what I was looking for. It checks all the boxes:

► colourful space theme
► text easy to read on Bookmarks toolbar
► easy to spot active tab when I have a lot of tabs open (which is all the time)

I do a lot of online research and my tired old eyes are taking a beating with all these "dark mode" options across apps (and even windows itself ugh). I detest high-contrast themes without colourful content. So when I stumbled upon this theme tonight, it was a match made in heaven. :) Thanks Jeff P

~Dani