[left that other site]

Any reason why they included American Indian Colors (Black, White, Red, and Yellow) into this design?

These colors represent the Four Directions and the Four major races of Mankind. FYI.

[C19fan]

Red and White are from St. George’s Cross and St. Andrew’s Cross representing England and Ireland. The Black and Yellow is St. David’s Cross representing Wales. I did not even know Wales had its own Saint flag as the Red Dragon Flag is much more famous.

[KarlInOhio]

Black and yellow are from the flag of St. David, Wales' patron saint. Or else they love Pittsburgh sports teams.

[Viennacon]

I think its to put to rest their old rhyme often said jokingly. ‘There ain’t no black in the union jack’, which was used to insult Pakistanis. The kaleidoscope flag is.... strange