Regarding the various racial slurs:  any suggestion of skin color beyond 'white' was relatively neutral, but none of the terms (yellow, black, red, brown) was exactly 'PC.'  In general, I'm expecting there's a lot more to be said of tone and intention than the actual word.  Intolerance will be more a matter of what and how it's said than the particular word used, because I think the culture was sufficiently ethnocentric at the time that any mention of someone's skin tone (if they weren't clearly caucasian) was fully intended to be disparaging in some fashion.  Also, a certain degree of racism is the norm in this era, not the exception, so someone who actually possesses an intolerance will have work to make their dislike for a different ethnicity particularly virulent simply to have it be noticeable.