The second question should have a different color since I favorited 'tags'. While the RGB values I picked from the picture try to convince me of a difference between the background of the second question I can honestly not see it (I am a bit red-green color blind). Can we get something that looks actually a bit different for the 5% with a color deficiency?
The background color of page elements marked tagged-interesting should be changed from the color #fafafb. That color is basically indistinguishable from the default background. It should be darkened. The color #eff0f1, which is already in the scheme for code blocks and blockquotes, would do fine.
I have flagged this as a bug. The site design clearly intends questions marked tagged-interesting to have a contrasting color. This is a problem in implementation, i.e., a bug. Probably easily squashed.
I can't tell the difference in the original screenshot and I have regular color vision. However, things have changed since then and I can now see the highlight for followed tags. Looking at color blindness simulators, I can even see the difference in monochrome, though it's subtle. There's also now an eyeball on any tags that you're following for an additional visual cue.
Regular:
Greyscale:
