Brown Pants/Shirts is a slur used to describe Italians in a derogatory way. From the color of their uniforms in WW II. Said by American GIs to hide when they defecate themselves on the battlefield.
The word Brown Pants/Shirts is a racial slur that has been used historically to degrade and dehumanize italians. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to italians. If you are unsure about whether or not it is appropriate to use the word Brown Pants/Shirts, it is best to err on the side of caution and avoid using it in any situation.