How to get back colored app headers in recent apps list?

Before, in recent apps list of my phone (Galaxy Note8), headers of apps were colored.
Now, they are all white.

I am not sure whether it was caused by transition from Nougat (7.1) to Oreo (8.0) or by a change in some Android settings. They are white for several months.

I would like to return to colored ones for faster navigation using app colors. Is it possible?