My justification is simply it isn't permenant and can change tomorrow should I wish. Yes I could change it, but it's white underneath and questions could be asked the other way.
My car is white, but with a blue wrap. I don't mind being stopped and actively encourage it as I drive a lot at prime crime time. Paint I can understand.
My insurance company don't care and still tell me it's white despite know there USA blue wrap on.
Of course, changing the log book won't do any harm.