White Is White, Except When It Isn’t

simulated color shift across different displays

Many factors affect color accuracy when creating and editing digital images. As with print, color on the web depends on the environment in which the image is created. Unlike print, web-based images can change every time they’re displayed because the monitors of users will vary, and no press check can catch problems that crop up.

Although many modern web browsers can display CMYK images, most images for the web are based on the additive RGB color model. This model applies a mixture of red, green and blue to each pixel.

But not all monitors are built the same, and so a particular shade of orange could be inconsistent across different screens. Here are some of the causes of color change:

    • Slight changes between manufacturers and models account for slight inaccuracies in shade and hue.


    • Many screens (especially CRT monitors) change color over the years and even as they warm up over the course of a day.


    • Until recently, Mac OS X and Windows used two different “gammas,” which meant that images on Macs appeared brighter than ones on PC. Mac OS X 10.6 (Snow Leopard) uses the more common gamma of 2.2, which is the same as Windows and many televisions and camcorders.


  • People browse the web from many different locations and in many different lighting conditions. The effect of overhead lights and the amount and color of natural light all affect the appearance of color on the screen.

Below, different calibration shows that “white” is often an assumed color:

simulated color shift across different displays

1. The original image, shot under fluorescent light with a point-and-shoot camera.

2. Approximate color shift on a Mac before Snow Leopard.

3. Approximate color shift on an aging CRT monitor.

4. Close to true color, as seen on the laptop on which the photo was processed.

A slightly red monitor might show an otherwise perfect blue as slightly purple, or show a green with a yellow tinge. Monitors set too bright will wash out shadows and highlights; monitors set too dark will muddy shadows and increase the chance of color shift in highlights. For designers who care about these details, quality control is definitely a challenge.

Written by Ben Gremillion. Read the full article here: http://www.webdesignerdepot.com/2010/04/how-to-calibrate-color-for-the-web