They give themselves a time limit - usually no more than 30 minutes - and then they check off all their items and award points for each item and its colour.
Sometimes this is a more difficult game to play in Winter than it is, for example, in Spring, but it is always very interesting, and makes the bears look at all the things around them much more closely so they can see exactly what colour they are!
You could play this game in your garden, or when you are out and about.