I never seen tacos made of blue corn. It looks a bit weird but interesting. My first thought was: Why does he post pictures of rotten tortillas but than I read the text and now I'm curious...
The Internet says that the blue color comes from anthocyanins which are very healthy.
And the Internet is always right! ;-)
ahhahah internet is actually right this time.
Blue corn is really good in flavor too, the higher quality places that make their own tortillas kinda fight to get blue.