I opened a new bale of towels to wash before use. They are burgundy in colour, I usually only have white towels, but I wanted them for the spare room I've just painted white and one wall behind the new brass bed burgundy. It says on the label: 100% cotton. Wash dark colours separately. (ok there - it's this bit) Keep away from skin .
I can only assume it is to do with the dye , possibly the dye will come out on to your skin if you use them without washing them first. Towels must first be washed before use or they will not be absorbent . When you wash towels / tea towels NEVER use fabric conditioner ! It coats the towels in a type of perfumed oil which stops them from absorbing water.