Q: Color printers use Red, Yellow, and Blue. I've been told these are the Primary Colors. Which means you can use these three colors to create any color visible to the human eye... So why do monitors use Red, Green, Blue instead?? This question has been nagging at me since the early 80's when I saw my first color monitor with 4 BNC connectors hanging out the back (the 4th was the sync). Even LCD moniors today still use the three color channels of Red Green and Blue. A brand-new nVidia board will have those three channels under the "Adjust Desktop Colors" screen of the Advanced options. So what's the deal? Why RGB instead of RYB?? Can't have to do with the way different frequency photons illuminate the phospherous lining of the CRT since they still use the RGB standad for LCD monitors... This is the first and probably last question I'll ever ask on Yahoo! Answers, so please don't answer if you don't know. This is genuine curiosity.
A: There are two sets of primary colours, one is for when colour is added the other is when colour is removed. With a monitor red, green and blue are added together going from black when none of the colours are present to white when they are equal but with ink each time a colour is added you are subtracting colour from white giving black when red, yellow and blue are equal.