Firefox and Serpent also have a few hidden 'developer' themes built in. With that in mind, I'll share my first trick. So the purpose of this topic is twofold: One, to solicit knowledge about legacy themes that can be downloaded and installed on these browsers two to share tricks that might allow more 'modern' themes to work. It would be nice if these browsers could provide error messages more meaningful than 'appears to be corrupt.')Īnd of course Firefox 52.9 doesn't even have those limited options! (Digression: I remember having that problem with an 'ID-less' add-on not that long ago, and the Firefox 53 themes indeed seem to be 'ID-less.' But going through the rigamarole of inserting an ID into manifest.json and removing the META-INF digital signature folder still doesn't allow these themes to install. And while Serpent 55 was forked from Firefox 53, none of the Firefox 53 themes I tried would work with it it just kept saying the downloaded theme 'appears to be corrupt.'

The 'Photon' theme doesn't work with Serpent 55, but even if it did, that's still not a huge selection of themes. Serpent 55 does have a couple of built-in themes besides the default: a 'dark' and a 'light' theme. It does a good job of making Serpent 52 look like the newer Firefox browsers, but 'Photon' isn't everyone's cup of tea. This has left users of Firefox 52.9 (and Serpent) without a lot of options to change the look and feel of these browsers.įor Serpent 52, about the only theme I found besides the default is a 'Photon' theme, available at. But while developers have created several repositories of legacy add-ons, I'm not aware of any repository for legacy themes. At least, the only the ones I could find at AMO were for Firefox 53 and up. When Mozilla nuked all 'legacy' add-ons from AMO, it appears they also nuked all the 'legacy' themes for the older browsers too.

Mozilla firefox themes for windows 10