From legacy/trac#30429 >We need an updated logo for aboutdebugging-firefox-release.svg > ... >(one can see the issue after flipping devtools.aboutdebugging.new-enabled and then opening about:debugging) While fixing the above issue for legacy/trac#30429, we realized that aboutdebugging-firefox-logo.svg also needs to be replaced. It's a black and white logo that will be colorized when the user selects it. For an example see: https://searchfox.org/mozilla-esr68/source/devtools/client/themes/images/aboutdebugging-firefox-logo.svg