Hi, I'm taking a look a which colors are the canonical ones for the kasinas, and found there is some conflict between sources.

Some say that the Nila kasina is green and others say it's blue.

I remember hearing that there are some countries in Asia that consider blue and green to be the same color.

I know kasina colors don't need to be so accurate, but which color is the canonical Nila kasina? Green or Blue?

If you're referring to an ancient Indian language such as Pali, then Nila is blue in general.

In the books I've read on Jhana based on the teachings of Pa Auk, the authors said that the nila kasina is actually closer to black. It's not a pure black though, it's more like the shiny almost black-blue-brown like the shell of a beetle, or a piece of polished jet. I think the idea is that it's basically a dark color, but despite being dark it is still luminous, not just the absence of light.

Nila is blue.

Follow up reference for my claim that nila is black.

From Wisdom Wide and Deep by Shaila Catherine, p.122.