Background color of Stack Overflow questions [duplicate]

Question

Why is the background of some questions light orange and some white?

Answer 1

Light orange means it's tagged with one of your "interesting tags", white means it's not.

See here and here for some more information.

Answer 2

The light orange questions are in tags that you marked as interesting in your profile page.

This allows you to ignore questions in topics that you aren't interested in.