a reply to: Abednego
Here we go...this is something that I learned in graphic design school:
Emitted Color (Additive Color)
First, there is emitted color, or simply put, light. White light, such as that emitted from the sun, actually contains all colors, which is the reason
that you can hold up a prism and watch it separate all of the colors into individual hues. There is no such thing as black light--that is called
darkness, or a lack of light. That contains zero colors (hues) because, as I stated, light is what produces the color.
These colors are reproduced using RGB (Red, Green, Blue) in our modern screens today, and you can get a true black on the screen by removing
each color down to zero. You get white by adding
all the colors together. The levels for each color run from zero to 255, so if each color is
set to zero, you have black; if each is at 255, you have white.
Reflected Color (Subtractive Color)
The other type of color is created by light reflecting off of a surface. When you have a red shirt on, that shirt is red because it absorbs all of the
other colors produced by a light and only reflects the red to your eye. Grass is green because all other colors are absorbed and the green is
reflected to your eye. Et cetera, blah blah, woof woof.
The actual primary colors, contrary to popular belief, are not the blue-red-yellow combo that we are taught as children, but are instead a combo of
cyan-magenta-yellow. Red is created by combinine magenta and yellow. Blue is obtained by mixing cyan and magenta. If you combine all of these
together, you do not get black (nor do you when combining BRY), but a muddy grey mixture. In printing, black is added in, and is a pigment that is
found in nature and doesn't have to be mixed with anything else to achieve it. "K" is the symbol for black.
This is why, when you look look at printer cartridges, you see CMYK (or variants of, like "light cyan") and not BRY. And if you really want a deep
black, you create a "rich black," by adding in percentages of all the CMY colors (my preference is 30%, 20%, 20%, but can change).
I hope this helps.
ETA: This is why you have different "white balance" settings on cameras, because of the color of the light--incandescent lights produce a yellow hue,
so it makes everything look yellow, whereas flourescent lights generally produce a blue hue to the image. This is all based on the assumption that
your white balance is set for sunlight, which is the standard that reproduces true color properly.
edit on 19-11-2014 by SlapMonkey because:
(no reason given)