You're not the first to post about that section of the Gauntlet. Sadly, Bungie's colorblind modes don't work on those red circles. I'd highly suggest posting in #feedback about the issue so the proper people can see this needed change that the dev team seems to have overlooked an actual game mechanic that causes issues and should be fixed by Colorblind mode but isn't. Try not to be mad, though, it's a somewhat easy oversight; Bungie's not even required to have colorblind settings, but the fact that they do and then created a mechanic that interferes with people with certain types of colorblindness just makes it seem like it was an oversight. I understand it can be frustrating when a part of the game seems locked behind such an issue, but there are ways that you can be the runner without being able to fully see the circle, it's just much much more difficult (which doesn't help with frustration, I know). Until Bungie takes note of it and can fix it, though, you'll have to make do; post in #feedback and hope someone on the feedback team that's there to find such feedback sees it and takes note of it being an actual issue.