It's more likely that your browser just isn't loading the CSS background images for some reason. If you inspect the circles, do you still see the background-image declaration?
Honestly, it's not hard. Just don't design everything around color. On ticket to ride, the grey lines ones have a dot or shape in the middle whereas the black ones do not. I can see that dot, but it's small. If it was larger then the problem would be solved.
Heck, I'm not colorblind and I had trouble seeing the difference between "service disruption" and "service outage" at first in the legend at the bottom of the page.
It wasn't until I zoomed in on them that I could see that one was orange and the other red. Once I saw them zoomed, I could then identify which was which at normal size on the status part of the page.
BTW, the orange circle is actually a span whose class is "aad-yellow-circle", and whose CSS loads the colored circle from the file yellow_circle.png.
This suggests that at one time they intended it to be a yellow circle, not an orange circle [1]. I wonder why they switched from yellow to orange?
[1] Actually, RGB to name sites suggest that it is neon carrot.
If the user had e.g. red/green colorblindness, that wouldn't help. Google's made a nice tradeoff for this application, though, and used differently-shaped icons (checkmark vs. exclamation point) as well.
Edit: looks like the icons are served as images. Google should probably consider making them text icons instead to mitigate loading problems.
