https://help.gnome.org/admin/

link contrast seems like it could be problematic for low vision and those with trouble viewing colour. I have uploaded a reverse video screenshot to help visualise the way this limits a users ability to correct that with their own browser plugins alone. 

It would be handy to increase the contrast of links at the source to simplify contrast control. 

Please note also that whilst high contrast is important for low vision users conversely certain strong colours like orange and red could also trigger migraine and even trigger fits for other users when taking contrast into consideration. 

As a migraine sufferer myself, I can confirm that a font colour like #EF8E4F; would be a barrier to reading the text itself for me, but not a trigger to look at. However, certain types of red are almost guaranteed to trigger a migraine on sight so this is also something to consider as well.