He has already said "overweight". The last thing he needs is to be lit up like a lighthouse. Just some subtle clothing will be fine. Then let your personality take over and see what happens.
Please read with more care. There is a difference between big and overweight, which i, and i presume you, don't know which Neg is.
If he thinks he is overweight then of course white would be wrong for him, but if he is just a big lad, then white would be ok.
And please don't exagerate, i mean a lighthouse for christs sake.