The white ghutrah represents that the person has not been on Hajj. The red and white represents that the person comes from a kingdom (UAE, Saudi Arabia, Oman, etc) and has been on Hajj. The black and white represents that the person comes from a republic (Egypt, Syria, Libya, etc) and has been on Hajj. This is what usually gets westerners in trouble in places like Dubai, etc with claims that they are disrespecting their national dress as they never wear the proper ghutrah i.e. Most westerners should be wearing the white one if any