Weird Issue Red pixels on Mojave Dark Mode


macrumors 6502a
Feb 5, 2008
I had the same issue on my MBP and Firefox. I fixed the issue by disabling the Firefox dark theme and downloading a new dark theme (Arc Dark). That was a couple of weeks ago with no issues since.


macrumors 6502
Dec 4, 2013
I've seen it at the top edge of a firefox window. Not sure what that is but probably some kind of bug.


macrumors 68020
Dec 7, 2016
Seattle, WA
Same bug appears on the MacBook Pro in Chrome as well. I haven't tried switching to the light theme to see if it goes away.

Barna Biro

macrumors 6502a
Sep 25, 2011
Zug, Switzerland
I've noticed these on my retina MBA too and I initially thought it's perhaps a faulty display. After a while it was more clear that it's either the GPU, the graphics driver or some other software related issue. I tend to notice them quite easily, but it is thankfully not happening super-often. Still blows a bit, but future updates should fix it, so that's good news (PS: it's not limited to FireFox, in my experience at least, it can happen in any app... seen these red/white/gray pixels in Safari, Chrome, as well as VLC, Finder, Mail, etc.).
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macrumors newbie
Jul 31, 2010
i've also got the weird red pixel. 2019 15" mbp, mojave, dark mode (haven't tested non-dark mode). but not using firefox here. i see it in chrome (no themes), VLC and safari (occasional use) - usually notice it when i'm fullscreen watching a show via one of the aforementioned apps. both top (menubar area) and towards bottom of screen. sometimes it's just a quick appearance and sometimes it blinks once or twice before disappearing.