question regarding background color

wheresdavid

I am going back to a village next week to take some "portraits" of a minority group in northern vietnam and was wondering what color background do you think is best. i will take environmental portraits but i also want to take some "portraits"

i have found a few different colored walls or doors to use, I am still trying to find a dark green one. of the three colors below which do you think is the best given their clothing ...
Thank you for your help!

cheers,
Dave