They are dyed, although the price sounds a bargain (but you are confusing me lol) they have been injected with dye through a needle. The nearest omparison is having an injection with a pencil...
One of my LFS's has recently started selling some silvery grey "Platinum Tiger Barbs" which they say are a colour form of the wild type - in the same way as the green and the albino. Are these different?
I have also seen Tiger barbs labelled as Platinum and they certainly didn't look dyed, i assumed they were a genetically engineered morph like the Albino.