On some questions, there is a blue tint in the background. What does it mean?
Some reasons I've eliminated due to inconsistency:
- Reputation of asker
- On Hold
This is most likely the 'Favorite Tag' feature in action. Similar to the main site:
Tags you have marked as favorite will show up with a yellow background. In the case of the iOS app, the theme is slightly different, so they show up with a blue tint.