what are the ‘real’ primary colors? the red, yellow and blue of the conventional color wheel? or the printer’s yellow, magenta and cyan? or the primaries for mixing colored lights – red, green, and blue?

why are there 3 primary colors in the first place and not for example 7?

why do colors form a circle, when the spectrum does not?

color

these and a lot of other questions are discussed at http://www.huevaluechroma.com, a website by david briggs on the dimensions of color and light perception.

sometimes a bit heavy on the technical side of things. and it may leave you even more confused then before. but still a great read for anybody interested in more than the absolute basics of color theory.