It’s better than that. There isn’t a single definition for white. Perhaps someone has one.

The best I can do, having studied Color Science at RIT, is that white is any spectral power distribution a person identifies as white. Yes, it’s a circular definition.

The topic is deeper than it might seem. I can put someone in a room and show them a color they would swear to be white. And then, in an instant, I can change that color by changing the surround, what you see peripherally. It’s freaky.

Did the course use a particular text? As an oil painter I'm interested in rigorous color science, but I have no affiliation with a university.

It's been about 15 years. There were a number of books as well as other materials. If I remember correctly this was one of them:

https://www.amazon.com/Appearance-Models-Imaging-Science-Tec...

I went looking around to see if I could find a better resource to help you dive into the topic in a more accessible manner. To my surprise Khan Academy seems to have a decent sequence of lectures on Color Science. I didn't watch the videos but the topics cover a reasonable portion of the basic knowledge one needs to start exploring Color Science:

https://www.khanacademy.org/partner-content/pixar/color

Perfect, thank you!

Joseph Albers' 'Interaction of Color' covers how perception of color differs based on context.