[3 years later…]
I agree, the link contrast is way too low, sometimes I can hardly read them.
The ratio doesn’t meet the WCAG AA accessibility guidelines:
Chrome devtools suggests #428fd0 which gives 4.59:
That would gives us something much better:
Ideally this would be suggested and fixed upstream at https://meta.discourse.org, but as suggested by @CAM-Gerlach over here, admins can also add custom CSS.