Class Resources > Color > Introduction to Color in Digital Media


Introduction to Color in Digital Media

Additive Color Theory
Electronic media uses an additive color scheme of red, green and blue (RGB) to make up the colors of the spectrum. A mixture of different colors will be interpreted by the brain as a single color. The same applies when different color dots are so close to together that the eye is unable to see them as seperate.

When the three primary colors are of equal intensity, they mix to make a pure white. When two primary colors overlap, a third color is produced; a secondary color. If none of the additive primaries are present you perceive black.

The additive color system follows that when red and green are mixed, they produce yellow. When red and blue are mixed, the result is purple (magenta). Blue and green make up cyan blue.

Subtractive Color Theory
The subtractive color system consists of the primary colors; cyan, magenta and yellow. When these colors are mixed in equal intensity they produce black (or rather a deep dark brown). This system is known by the abbreviation CMYK (cyan, magenta, yellow and black) and i t forms the basis of the printng process.

In the color printing process, the white paper is thought of as reflected white light. As printing inks are transparent, each ink layer acts like a color filter that can block a certain portion of the light.

Web designers soon realize that color callibration or rather lack of it, prevents them from having colors look the same on every system. Macs and PC's and other computer platforms such as Unix, all have different color cards and monitors and none of them are calibrated to each other.


Calibration
Calibration is made up three major variables; phosphor color, white point and gamma. Macs and PC's and other computer manufacturers all have different color cards and monitors and none of them are calibrated to each other.

Lets put this into the context of a real life designing situation. Imagine if you were designing an online clothing catalogue, that red blouse on the online catalogue had better be the right red, the same red as the blouse. In other words, you would want to be able to display a specific color exactly. However, it's virtually impossible to match an electronic color with that color printed on paper. There is color calibration software, however this is the number one problem in the graphics industry and it is far from solved.

Don't become frustrated when trying to print out an image and it looks different than that on your monitor. You are not the only one this happens to. And to add another variable or two, the colors will vary depending on the kind of printer, and yes even the paper.

If you are interested in printing some of your assignments you can read ahead on 'Printing to an Inkjet Printer' in your One on One Photoshop CS3 text. [Page 472-485] This section reviews 'source space' the color used by the image itself and the method Photoshop translates the colors to the 'destination space' used by the printer.

While not all print manufacturers allow you to modify the color management method, Epson printers typically do. Also, many digital media students realize that when it comes to printing RGB files on a CMYK printer, Apple's ColorSync color matching software (built into OS X) delivers satisfying results. As much as pc's outsell macs in the consumer market, the mac has built in tools that enable photographers, graphic artists, and other creatives to better manage their production and work flow.

One Last Bit
Just one more bit about the digital aspects of color. On a monitor, each little pixel can be represented by a variable number of bits used to describe the color of the pixel . Bit depth is the number of bits used. A bit depth of two means that only black or white pixels can be shown. Bit depth equals the number of colors.

Bit Depth Number of Colors:
2 ...............................4
8............................... 256
16............................. 65,536
24 .............................16,777,216

Understanding bit depth is important for two reasons. One it controls the amount of colors you can view on your monitor, and two certain graphic file formats are bit depth dependent. Older monitors have 8 bit graphic cards, which you may deduce from above allows the viewer to see only 256 colors. Due to the popularity of interactive games, and the dropping price of monitors, most computer owners in the US have monitors that can display millions of colors.

Regarding the bit depth of an image, we understand that higher bit depth equals more colors. Therefore, higher bit depth equals larger file size. Gif is one of the graphic file formats for viewing graphics on browsers. Gifs can be saved from 8 bits down to 1. The other common graphic format for the web is jpeg. Jpeg supports 32 bit color or millions of colors. This fact alone should tell us that the jpeg format is more commonly used for photographs, and that gif is more commonly used for logos, and other solid color art work.