This is awesome !!! Thanks !

So this is the replacement of Personas Plus. Well it's not as good, that the least to say.
- On its customiser page, Personas Plus had a very convenient colour picker. Firefox Color hasn't. One star disappears.
- While the interface is efficient and easy to use, I could only use it once. Indeed, from the time I saved the theme, I couldn't go back to the interface, neither with the add-on button nor the URL. I only get a flash of that quote page and that's it. One other star disappears.
- If theme is changed via add-ons menu, where by the way saved theme from F Color isn't even listed, you can reload this saved theme by clicking the add-on button, only if all F Color tabs are closed. One other star disappears.

Maybe the problem comes from my OS which is Linux Mint 19.1 Cinnamon 64-bit.

Personas Plus has less fancy options than its successor but at least still works to apply a custom theme. I stick to it for the moment.

Me gusto mucho poder cambiar el diseño del navegador c: Mozilla es mi navegador favorito pero su interfaz era mas o menos, ahora esta mucho mas bella

It's so easy to use.
And the effect kicks in immediately (don't need to restart your browser), which is awesome.

I like the concept, but I miss the older cool looking themes like Lavafox Themes.. :/

Anyways, the NewTabPage (NTP) needs to be added as well.

Tento program není špatný, jenom by to chtělo vydat konečně plnou verzi a nějaký malý fix protože když si vytvoříte vzhled tak poté co program uzavřete tak už jej po druhé nespustíte. Načte se jen prázdná stránka.

incrível, uma das melhores ferramentas do mozilla.

Trying to upload the themes created results in error messages: "This theme LWT alias is deprecated.

Warning: See https://mzl.la/2T11Lkc (MDN Docs) for more information."

A bit silly for it to have conflicts with the features it was intended for.