On SO, when I'm scrolling through "questions" some have a yellow background. Is this intuitive to everyone but me? What is the yellow background trying to tell me about this particular question?
4 Answers
The questions highlighted in yellow have tags you have marked as watched. Questions appearing grayed out you have marked as ignored. You can manage these either on the front page or on the preferences page of your profile.
- 18Wow. That's great. Although it wasn't intuitive to me when I saw the color. I wonder if a tooltip or something is warranted here?Kurt W. Leucht– Kurt W. Leucht2009-07-30 20:23:12 +00:00Commented Jul 30, 2009 at 20:23
- Was pretty intuitive for me =/Ian Elliott– Ian Elliott2009-07-30 20:29:58 +00:00Commented Jul 30, 2009 at 20:29
- 92totally non-intuitive to me. I specifically came to meta today to find out why this was happening.Taryn East– Taryn East2011-05-17 08:31:30 +00:00Commented May 17, 2011 at 8:31
- 5Non-intuitive for me also.Bear. Teddy Bear.– Bear. Teddy Bear.2011-06-02 16:21:40 +00:00Commented Jun 2, 2011 at 16:21
- 5I also came to meta today just to find out about the yellow background (and imported my account just to leave this comment). At first I assumed that they were newer questions or questions with less satisfactory answers.octern– octern2012-03-12 17:46:56 +00:00Commented Mar 12, 2012 at 17:46
- I too had to come here and find out why some of the questions were highlighted. Now it makes sense.Miguel-F– Miguel-F2012-09-06 19:08:51 +00:00Commented Sep 6, 2012 at 19:08
- 3Non-intuitive. Just searched Google to find an answer to this question.Trevor Sullivan– Trevor Sullivan2014-01-08 14:01:58 +00:00Commented Jan 8, 2014 at 14:01
- Obvious now I read this, totally wasn't beforeMatt Harrison– Matt Harrison2014-07-24 05:27:08 +00:00Commented Jul 24, 2014 at 5:27
- 9I just tried to upvote this answer, then found I voted it already 3 years ago. So not only is it not intuitive, it's not memorable :(barryhunter– barryhunter2015-02-18 17:49:18 +00:00Commented Feb 18, 2015 at 17:49
- 2Are we sure this is correct. I have the tag "css" added as a favorite and I've posted a question that is tagged with "css". When I navigate questions with the "css" tag, my question is white, when I navigate to "html" where my question also shows up, it's yellow.ThrowBackDewd– ThrowBackDewd2016-03-31 01:14:48 +00:00Commented Mar 31, 2016 at 1:14
- 1I browse only my favourite tags but still a subsection gets highlighted yellow. This seems to be when the question contains 2 out of 3 of my tags.Nick Cardoso– Nick Cardoso2016-04-13 08:19:17 +00:00Commented Apr 13, 2016 at 8:19
- Did anyone else thought it indicates question got Flagged and waiting for moderation?Mohammad Yusuf– Mohammad Yusuf2016-12-02 14:59:49 +00:00Commented Dec 2, 2016 at 14:59
- Unintuitive what yellow means. Unuseful indicating favorites here. Unstable what this feature is even called: used to be called "favorite", or "interesting", now it's called "watched". Unstable where you control it: used to be able to change this set of tags from the profile, now it's on each tag page.Bob Stein– Bob Stein2018-09-09 23:39:13 +00:00Commented Sep 9, 2018 at 23:39
- 2MISSING PIECE: When you are browsing questions of a tag that you are following, that tag's questions are not highlighted yellow. The yellow highlighted ones have OTHER tags that you also follow. Here I see that flutter-only tagged questions are not highlighted even if I follow flutter: stackoverflow.com/questions/tagged/flutterGazihan Alankus– Gazihan Alankus2019-07-25 06:53:34 +00:00Commented Jul 25, 2019 at 6:53
There are two reasons a question can be marked as yellow.
Favorite tags
You can add favorite tags from the main page, or the prefs page (Link to prefs above bio in profile). They get highlighted on all pages (except for their own tag pages).

You can also ignore a tag, and it will grey out/disappear (depending on prefs and the page). Note that ignored tags have preference over favorite tags. In the example above, a question tagged javascriptfacebook will be greyed out.
Frequented tags
If you post on a tag often, and have a good enough score, the system decides you like the tag and auto-highlights it. This is only if you have not specified any other favorite tags.
Of course, it can lead to this{*}:

If you really don't want to choose favorite tags, then add some random nonsense tag to the list. SOmewhere on MSO, I saw frequentedtagsfail used for this, so I use it as well.

*That did happen to me. I was besieged by enticing yellow QM questions that I didn't know a thing about.