MrOtherGuy

Sounds like you are talking about Firefox's letterboxing feature which you can enable/disable independently from full fingerprinting resistance.

I'm not sure if resistFingerprinting does anything to stop websites from uploading whatever data they can get though, I don't think it does that. And I don't think it could really do that in the first place since the website could just obfuscate the data and browser wouldn't know what is sent.

You'll be styling another element, that's really all it is.

Normally Firefox applies various styling rules to the element with id urlbar-background - so it makes sense to also apply your custom style rules and overrides to it. If you apply your background-color or border or other rules to some other element such as #urlbar-input-container then the original styling of #urlbar-background still applies as well.

This would then cause issue like you would see in your first image, exactly like you guessed; the outline of #urlbar-background is seen behind the background-color of #urlbar-input-container because the two boxes don't have exactly the same shape and thus you are not fully covering the urlbar-background.

If you aren't doing anything else to urlbar then I'd recommend styling #urlbar-background instead of #urlbar-input-container - like this:

#urlbar-background {
  border: none !important;
  border-radius: 5px !important;
  background: light-dark(#ffffffff, #1b1e20ff) !important;
  outline: none !important;
}

That's not necessarily a good solution either, because a service could figure out that the source of random fingerprint data likely comes from the same user. Especially if your ip is not changing. It might perhaps be effective if a substantial amount of people were doing it though.

But to generate such random fingerprint is difficult because it consists of many parts and services don't all build fingerprints the aame way. You could easily randomize e.g. canvas data, but the issue is that if you only randomize one data point then that one random data point pretty uniquely identifies you if your other datapoints are stable. So to be effective you would really need to randomize several different datapoints and that may not be such an easy task since websites could build them in all sorts of ways.

You can change it like this with userContent.css:

@-moz-document url("about:newtab"), url("about:home"){
  :root{
    --newtab-primary-action-background: #f00 !important;
  }
}

That way you can specify a color for them, but setting the value to AccentColor may or may not resolve to the actual system accent color.

Yeah, regular http cache is indeed a thing. However it's more complicated because the web server can tell the browser how the returned content should be cached - if at all. So if, say, reddit servers ask the browser to not cache particular resource (for whatever reason) then it won't be cached. I mean, the browser is free to do as it pleases, but I think in general browsers would do as the server asked and indeed not cache it.

It's all good my dude. There's just so many small differences between just linux versions that I wouldn't have been suprised if the style didn't work in one of them.

Is your style up-to-date? This sort of sounds like issue #359 but that should have been fixed 2 months ago.

Well the feature development is certainly progressing - here is the tracking bug for it.

You can nowadays just test it in normal nightly without special build - it's extremely incomplete, but you can test it if you wish. It's tied to revorked sidebar which you need to enable in about:config.

I'm not sure about how the svg would work here (though it might work fine), but you can do that with just CSS as well:

@keyframes tab-gradient-anim{
  from{ background-position-x: 0% }
  to{ background-position-x: 200% }
}
.tab-content[selected]{
  background-image: linear-gradient(
        90deg,
        rgb(255, 0, 0) 0%,
        rgb(255, 154, 0) 12%,
        rgb(208, 222, 33) 24%,
        rgb(79, 220, 74) 35%,
        rgb(63, 218, 216) 44%,
        rgb(47, 201, 226) 50%,
        rgb(28, 127, 238) 60%,
        rgb(95, 21, 242) 70%,
        rgb(186, 12, 248) 80%,
        rgb(251, 7, 217) 90%,
        rgb(255, 0, 0) 100%
    );
  background-repeat: repeat-x;
  background-size: 200% 100%;
  animation: tab-gradient-anim 2s infinite linear;
  background-clip: text;
  color: transparent;
}

Absolutely not. If anything, public officials would be the one group whose messaging I would understand being scanned so that the people can sort of keep them on check. But again, implementing such possibility that would still weaken security of everyone else as well so of course it should not actually be done.