Years ago we read some of de Vries's papers in a radiocarbon course and the question came up about why he didn't win the Noble Prize alongside Libby. Pretty shocking 😮https://en.wikipedia.org/wiki/Hessel_de_Vries

That would have to Greenland. That said, I have stumbled across a mummified penguin when hunting for old ice in the Dry Valleys of Antarctica.

Colour is just depth. Changing the colours by age (linearly) would be tricky as the age of the ice increases rapidly at the very bottom of an ice core. And unfortunately we can't make an accurate map of those ages without more ice cores :)