Those are the characters you're talking about. Let's see if we can't sort this out.
Little Jerry, voiced by Jerry Nelson, green AM with orange stringy hair and rock star wardrobe.
Big Jeffy, voiced by Jeffrey Moss, blue bald-headed AM with brown beard and mustache wearing a blue top hat and loincloth type of clothes.
Rockin' Richard, voiced by Richard Hunt, tall orange cylinder-headed AM with black curly hair and dark reddish nose, not sure what he wears.
Chrissy, voiced by Christopher Cerf, small lavender AM with curly black hair and light pinkish nose, not sure what he's wearing.
Hope this helps and have a good day.