"black" cloth isn't black. It's always dark red, dark blue, or dark green.
Either your cloth gloves are bleeding when sweaty, a foam or cloth padding in a storage bin is bleeding when damp from sweaty armour, the black material from undergarments, socks, neckseal , balaclava is bleeding.
Just yesterday, for example, one of our at at drivers was trying to figure out what was staining his new grey jumpsuit yellow. Looked like random bleaching, but in straight lines and only on arms, legs, chest, random spots. He used mattress foam from Walmart to line his carry bin...same colour, and that foam isn't microfibre and very prone to colour transfer.