In reply to gethin_allen:
Can't see from that photo.
But, if you have doubts, take them back. As PPE, they are unlikely to offer their usual no quibble guarantee, but if you point out that you suspect them to be faulty (which, to prevent them simply going back on the shelf, you should), they really ought to respond appropriately. I'd probably ask to see the manager to return questionable PPE.
The same artefacts on four items, of different colours, so likely to be different batches, suggests it's unlikely to be an issue. I think if I were a manufacturer, I wouldn't want my products to look like they might have manufacturing faults, so I would modify my process to eliminate such cosmetic flaws...