The fact is, they made a change that may improve the user experience for one group while ignoring the user experience for others. This new design is not accessible!
Because the current design relies almost exclusively on color, people with certain types of colorblindness will find it especially hard to tell that a question is ignored. (The exact type of colorblindness affected may depend on what site, though those with monochromatic vision will likely struggle no matter what). In fact, even with normal vision I struggle to see the difference until after I read the title and see the tags, due to a combination of subtle color differences, color differences between site themes, and color differences between visited and unvisited links:
Additionally, screen reader users are given no indication at all that a question should be ignored. Literally nothing changes between ignored and non-ignored questions (as far as the screen reader can see), so the content is just read out loud no matter what.
Consider instead a design where ignored questions are collapsed in place (so you will see non ignored questions between collapsed ignored questions), and shown on click/tap, similar to Discord:
This makes it not matter what color ignored questions are. It also fixes some more obscure issues like how to keep ignored question titles from being indiscriminately revealed by screen readers when they are only reading the links on a page. As a bonus, it fixes things for people with wandering eyes who can't help but read everything that's visible no matter what color it is (yes that's me, even with the old design).