If veins looks blue because red light doesn’t escape through the skin, how can we look bright red when we get sunburn?
The critical part of the article is “At a certain depth, the tubes appeared blue.” A one-molecule-thick layer of skin overtop of a capillary is not going to make it turn blue, and the inflammation that comprises a sunburn is closer to the surface than a vein.
If I had to carry poop and pee, I’d be blue too … what a nasty job.