Hah, thanks! I should have been a little bit clearer - not an ELI5-layperson, a layperson who has some vague handwavey idea of how video/film is made and once read a popular article about orange/teal contrast.

It's more stuff like 'what is it about this process that makes a dedicated colour specialist necessary?', 'what are the things things they're supposed to accomplish?', 'what are their technical and creative constraints/inputs/deliverables?', etc.