Re Another Question

How does one introduce non-white characters in such a way that readers don't see them as white?

This is problem, if the author is white. I mentioned that readers see Li Li-xia in A Woman of the Iron People as white, in spite of her name. Granted, she has spent much of her life in the Middle West, so she comes off as a Midwesterner. Many people seem to think Midwesterners are all white. They apparently have not heard of Chicago or Detroit.

I suspect readers also see the heroine in Ring of Swords as white, though her name is Anna Perez, her skin is brown, and I mention that she has a Mayan profile.

It's comparatively easy to introduce a non-viewpoint character and make clear how he or she looks. Just say it: the character is black. The character is East Asian descent. Of course, you have to assume a society that still notices these things.

In my Lydia Duluth stories, most humans are dark brown or black, due to genetic modification to protect their skins from the radiation of many different stars. My heroine -- Lydia -- is light brown, because she comes from a conservative colony that does not believe in gene mod. She uses a product called Dixie Plum Skin Darkener when she is on a planet with radiation that worries her. I mention some or all of this in each story.

With a viewpoint character, you may have to use techniques such as looking in a mirror. It's tedious, but it gets the message across. A simple statement of where the character is from may help. If she is from India and her last name is Chatterjee, people really should figure out that she is Indian.

You may have to make the point more than once, since white is the default color -- at least for white readers reading a white author. Talk about the ancestral home on the Bay of Bengal, which got flooded when sea levels rose. Talk about favorite foods. (This will allow you to do research in Indian restaurants, a bonus.) Look up Indian holidays and mention them. If the character is several generations away from India, you need not do a lot of research. But favorite foods often last for several generations, as do holidays...