Question regarding "color of law"-- Any lawyers in the house?

[therehegoes]

If law enforcement personnel commit crimes and/or go beyond their authority while wearing street clothes (and not in uniform as they normally are when performing those acts), do they forfeit protection under color of law statutes? I'm assuming that by committing crimes and/or abusing their authority and acting with malice, they automatically forfeit protection, but being that that veil is so difficult to pierce, I also assume that the street clothes and retaliation outside the hours of normal harassment, that this might also endanger their protection under the "blue curtain".

Any thoughts on this aspect?