This is a HNQ excerpt from Stack Overflow. Visited questions are objectively darker.
This is a HNQ excerpt from Super User. Visited questions are objectively lighter.
This is a HNQ excerpt from Seasoned Advice. Visited questions are objectively darker.
This is a HNQ excerpt from Puzzling, a beta site. Visited questions are objectively darker, although the difference is hard to spot.
This is a HNQ excerpt from Travel. Visited questions actually have a completely different color.
These are 5 different sites, with 5 different formats for how the HNQ sidebar displays links. Some make visited links darker. Some make them lighter. Some make them a little big darker. some give visited links a completely different color. This is very confusing: If someone visits one of these HNQ questions and wants to continue browsing the HNQ from there, they likely expect that the links in that HNQ segment have consistent layout compared to the HNQ segment from the website they came from.
Is this something worth looking into? I realize that each site has their own look and feel, but an element that appears on every site should be consistent IMHO. People have expectations about how links work, and one of those is that if you click on a link within the same domain (which the HNQ segment arguably is), they behave similary on that page as they do on the page you come from.