2011-09-22 : A multicolored creature with intimidate can be blocked by any creature that shares a color with it, in addition to artifact creatures. For example, a white-blue creature with intimidate can be blocked by white creatures and/or blue creatures, no matter what other colors they are.

2011-09-22 : If an attacking creature has intimidate, what colors it is matters only as the defending player declares blockers. Once it’s blocked, changing its colors won’t change that.