Colour modes
RGB is a three channel mode – 1 each for Red, Green and Blue
CYMK is a four channel mode – 1 each for cyan, yellow, magenta, and “key” which, to all intents and purposes, means black
Lab is a 3 channel mode – lightness, magenta/green and yellow/blue
For the time being we will stick with RGB Mode for our purposes of spreading enlightenment!
RGB, without any indication of “flavour” is pretty meaningless in terms of colour accuracy – it needs an identifier that tells us what flavour of RGB it is – e.g. sRGB, AdobeRGB etc. It then becomes a colour space identifier and the “profile” is usually attached to the file so that other systems can decide how to handle the colours i.e interpret the numbers 0 -255. An image without an attached profile is rather like having a piece of music without knowing the key. To continue the musical analogy, if all the instruments in a band are “in tune” they will sound good together. Similarly, if all the members of your club have correctly calibrated monitors you should all see each others images as the photographer intended.