Im not sure if this addon is ment seriously or it's just to troll people. There is no import functionality at all. The current theme will be completely ruined if i intent to change something like the tab highlight color. Dont waste my time with incompetently created addons like this.

This is, as far as I can tell, completely useless. Managed to get it to display a custom image, eventually and more by fluke than anything. The tab for the saved "themes" is hidden by the text box on smaller screens so didn't even find it until by chance looking on another computer. The main reason I wanted to customise the theme was so I could distinguish between personal/work profiles, but the "theme" doesn't sync when using Firefox Sync so this is not only unusable but also useless. Do not see the point of this add-on.
Also, minor annoyance, from the settings page there is a link that has been localised to say "Firefox Colour" but it is still called "Firefox Color" everywhere else. Pointless localisation there, either do it everywhere or nowhere.

Causes conflicts with Firefox's themes. Only use one or the other.

I just wanted to change my top bar colour to blue and it's so complicated? Other colours randomly changed on other UI elements that I didn't ask for? Could you have made this any more baffling?
I was also turned off by Firefox marketing associating "blue" with "activist". Yeh no thanks pal, I just like the colour, save me the cod psychology...

I just wanted to change my top bar color to purple and it's so complicated to do. I have to recreate the whole default theme from scratch and then tweak the purple. When I got to a result I liked I saved the preset. After a while I wanted to change the shade a little bit. I did so but I was not satisfied, and by mistake I clicked reset all, instead of Back. At that point I was screwed, had no idea where to find the saved themes, would have had to recreate the original theme once again so I gave up, uninstalled the extension and came here to write this review. Work on your UX because this is really awful.

Upgrading changes my background color scheme without permission. This has happened twice in the past 6 months.

no funciona

it works but sometimes it glitches and erases all the themes i have made, idk if it's just me or if this add-on is doing it

Nothing speacial. I just find good theme for myself and add it "Fankots Theme by Fantron".

The colors are nice to costumize. Unfortunately UNUSABLE because after opening Firefox it takes an additional 2 Minutes loading the theme before you can start doing anything.
How on earth can you design an addon JUST for some colors consuming SO MUCH ressources??? I really have to control my anger here. Unbelievable.

NO ME DEJA USAR LO QUE YO CREO , QUIERO FONDO GRIS !!!!, PORQUE NO HAY UN FONDO GRIS???,,,O ES BLANCO O ES NEGRO UNA PORQUERIA..!!!! ESTOY PODRIDO!!!

setting the toolbar color also changes the default background color for web pages; that should be a completely separate option

I installed the extension because I wanted to add color to the top bar. I made some changes and exited the setup to see the results. But I couldn't find a way to get back to the setup. Finally, I uninstalled it and reinstalled it. But the same thing happened; I couldn't get back to the setup page. So I'm going to uninstall it and hope I can find a way to actually use the extension.

Firefox Colors represents the whole sad history of Firefox and Mozilla. Starting with the best of intentions, and then like a machine rolling through mud, accumulating sludge as it progresses till it is unrecognisable and impossible to use. Gets a good cleanup and starts all over again.
I agree with many of the others, who, like me, are frustrated at this stupid implementation. Every change appears to be irreversible. I have lost all my careful colour setups of versions past. Oh well, there are probably some idiots in a room somewhere patting themselves on the back and thinking they did a great job - so this won't change.
It's okay, we are almost at the point in the Firefox cycle where I drop off and walk with relief towards Chrome...

I hate it

doesn't load the page, i opened the extension, went off, played a game for an hour, came back and was confused by a blank tab, only to realize, IT WAS THE EXTENSION PAGE. so...yeah, it doesn't work.

'Export' doesn't work.