I understand that if we look at an object, and it is blue, it is because the ball is actually “every color but blue, therefore reflecting the blue light.”
Is it possible to have an object that’s “every color but blue and ___”, (ie, 2 different colors). If it is possible, what color would we see the object to be?
That’s how you see different colors, other than primary colors, because more than one is reflecting.
It’s more complex than this, and I’m sure others will jump in with details, but generally, when you see brown, you are getting a mix of reflected colors, with the rest of the colors being absorbed, rather than reflected.