Colorful long underwear (thermals) - where to buy?

Carrying on from @Ian_H's comment, I'm not sure if they were made from scraps but even as recently as 10-15 years ago it wasn't uncommon to see bright stripy colourful thermal polyprop, and you could just buy them in most tramping shops. Having clashing colours all over you and poking out from under your shorts in winter was a backwards sort of fashion statement, and maybe sometimes still is for a joke if nothing else. I haven't seriously tried looking for it for some time, but I'm wondering if that culture's died a bit since more fashion-oriented brands like Icebreaker have started dominating more of the market with more expensive merino instead of cheaper and more expendable polypropylene.