I am a little confused. I am part of a marching band that practices in the heat very hard and i naturally am very sweaty. Since last season i have noticed a very distinct orange sweat that accumulates on my skin. Ive tried everything to figure out what it was. I only take a vanilla protein powder supplement and a multivitamin daily, both of which i stopped last season to see if it helped, and it didn't. I also do not notice the orange sweat during the offseason when i train. Could this be some other dietary excess? Im not sure if it something to be worried out, but i would like to know what causes it.
Could be orange chromhidrosis. I've had it before - when I've had too much carrot juice. Last time I thought it would be a good idea to drink about 2L (half gallon) of fresh carrot juice. 20+ carrots hitting the body all at once is not a good idea.
Another possibility is your multi-vitamin - if it's not timed release or if it's got like 1000% of the daily recommended limit of the B family, your body will excrete what it can't process - it'll come out in urine or sweat. I've had that happen, too.
(I don't see the protein powered having any influence)