Channels

Tina wants to create new colors to give a special look to the greeting card. She knows that Photoshop has channels and paths that will help her create a range of colors. Channels are like primary colors (raw information) and by mixing these you can create a gamut of colors. There are two kinds of channels.

CMYK Channels. CMYK stands for Cyan (blue), Magenta (red), Yellow and black. Black is added because mixing the other three colors produces a muddy brown rather than a pure black and there is no way to render a full color image correctly without using black. Since each color has its own channel there are four channels in the channels palette for a CMYK image. To look at just one channel click its name in the channels palette e.g if you click the Cyan channel the preview displays only the parts of the image that use Cyan ink.

CMYK Image showing the channels palette

Cyan Channel

Magenta Channel

Yellow Channel

Black Channel

Note: CMYK mode should be used only if you are preparing files to be printed on a commercial printing press. When creating documents it is best to work in RGB first and convert to CMYK at the end. CMYK colors are subtractive colors, which mean that if you take all the colors away only white will remain. The more color you add the darker the image will be.

RGB Channels. RGB stands for red green and blue. This is the main color space you use most of the time. These are additive color because the three colors combined make white. If you think CMYK as inks then RGB is like light. These are also called monitor primaries. The human eye sees in additive color. E.g. look at the red channel image. Imagine that instead of white we are showing red light; so where there is no red light it is shown as black and where there is intense red light it is shown as white. Hence no light would mean no color and a lot of light would mean a lot of color.

RGB image with Channels.

Red Channel

Green Channel

Blue Channel