When color isn't just color anymore
My background has been primarily dealing with digital devices which has allowed me to only work with RGB, blissfully unaware that anything else existed. Sure, I would see that there were other alternatives in dropdown lists of Photoshop, but what were those for anyway?
And then I started working on Genegrafter from a different angle: http://www.genegrafter.com. Moving from digital to print media meant that I needed a crash course in how they were different. So for anyone that doesn't know the difference, here is a quick run down.
What is a colorspace?
Wikipedia defines a color model as "colors [that] can be represented as tuples of numbers, typically as three or four values or color components". So the colorspace is a mapping between this model and our implementation of color. This is a fancy way of saying that we look at color differently depending on which color space we are using.
CMYK vs RGB
I mentioned RGB before, and this is what I've been used to. The reason is because RGB is what electronic devices use. It is an additive model, Red, Blue, and Green are added together to produce colors. You can't use this when printing in the real world however because this method would just give you a bunch of mottled browns and blacks.
CMYK is able to get around this because it is subtractive. Since the color white is actually the presence of all color (and conversely black means that all color is absent) we can add Cyan, Magenta, and Yellow (the CMY) to strip away (or subtract) colors from the white paper in order to get the colors we really want. This process can actually be affected by the starting color of our paper as well; printing on an off-white page would not be the same as if it had been pure white. K in CMYK is black and can actually be obtained by combining the cyan, magenta, and yellow but then we would have to use three times as much ink, so it's generally better to have a separate mix of black available.
The following is the same image but one is using CMYK and the other is RGB
The moral of the story is to make sure that if you ever plan on printing anything, you ready it as CMYK but use RGB for anything digital. Most of the time you will use one or the other, but every once in awhile you may want to cross over to the other side, and when you do, there are considerations to be made as seen in the image above.