Most people who do web or print design know this stuff, but just in case you missed the information or forgot it - here are some quick reminders

 

There are two basic color system choices when you are working with color on the computer. CMYK and RGB.

 

CMYK is the acronym for the basic colors (also called process colors or 4 color process) that are involved in printing images in color. C=cyan, M=magenta, Y=yellow and K=black. When a picture is printed on paper the colors are formed by a selection of each of these color dots.

 

If you want to change a color you can go into the color adjusting system and adjust each of these three basic colors separately. If you are designing something to be printed, this is the color system you would choose. If you combine all the colors to the max (excluding black) you get black - but not a clear black.

 

RGB is the system that you use with web design. R=Red, G=Green and B=Blue. Unlike CMYK, if you mix these colors together you get white (like a prism in reverse). Unlike CMYK which is meant to have opaque ink placed on paper, RGB colors are meant to have light shine through them like a stained glass window.

 

Black and White -Black and White is just that, no grey. This is great for ink on paper expressions. Typography treatments. And what you will get is real black on white - not the first 3 colors in CMYK mixed up into a sludgy black-looking color.

 

Grayscale - If you want to convert a color image into "black and white" image you probably want to use grayscale. This gives you not only the black and white but the grays. This is also called desaturating or removing color. You keep the values of the image - the lights and darks - but not the color.

 

Spot color - In the printing world there is Black/White (which usually means grayscale), spot color (a single color that is often used to liven up a black/white piece and 4 or 6 color process. Spot color is a single color used for accent.

 

Duotone - This is a combination of grayscale and spot color. It gives you a sophisticated image which is more interesting than a Black/White image but less common that a 4 color image.  

 

I won't even attempt to go beyond this with colors. Color theory and techniques can take up whole books. But sometimes it helps to review the basics. Just in case some asks "What does CMYK stand for?