Web Page Color

Computer video displays typically show 256 colors, thousands of colors, or millions of colors.  The number is determined by the amount of RAM on the video board, the software used to access it, and software settings.  The number of bits used by the video board determines the number of colors which can be displayed:

 Bits    Colors 
8   256   
16   65,536  (thousands)
24   16,777,216  (millions)
32   16,777,216  (millions)

32-bit color doesn't give more colors than 24-bit, but does allow other display functions in certain programs, and may increase display speed since it requires fewer calculations.  I recommend setting your color depth to 24 or 32 bits for the best color.  Older boards with less RAM may have limited screen sizes at these settings.


How to Adjust Color Depth

You can adjust these settings in Windows via the Start button / Settings / Control Panel / Display, or by right-clicking in an empty area of the desktop and selecting "Properties".  On the Display Properties sheet, select the Settings tab.  Also, most video controller board manufacturers include software controls, usually accessed via an icon in the box at the right end of the Taskbar.

Some programs, including some browsers, must be restarted after increasing color depth in order to display correctly.


A Problem With 16-Bit Color

Here is a very nice photo of a Delta 2 launch vehicle taking off from Vandenberg Air Force Base in California.  It is a large image, 1200 x 800 pixels, but the file size is only 168 kB, so it should take less than a minute to receive even over a slow modem:  Delta 2 launch

This photo is encoded in 24-bit color.  The sky and ocean are smoothly-graded shades of blue.  If your video display is set to 16-bit color, you'll see ragged bands across the sky and ocean.  It almost looks like a different picture.  To show smooth gradations, a large number of colors must be used.  16-bit color can't do it.


The Other Problem With 16-Bit Color

A second problem is caused by programming errors in the conversion of web page colors to video display system colors.  It happens when text and background colors are converted one way and image colors are converted another way.  Most browsers have this problem.  Your browser has the problem if you see faint squares inside any of these rectangles when your video display is set to 16-bit color:

                                                               

When your video display is set to 24-bit or 32-bit color, no color conversion needs to be done, so not only are colors usually more accurate, but web pages display a little faster, too!


Eliminate Reflections

One of the most effective things you can do to get the best color from a monitor is to minimize the amount of light hitting the screen.  Obviously, you should position lights or move your monitor so light doesn't fall directly on the screen.  In addition, you should minimize the amount of light reflected by objects in front of the screen -- including yourself!  Light shining on you or on a light-colored wall or object behind you will be visible in your screen, reducing the contrast.

The best placement for lights may be overhead, in the narrow space between you and the monitor screen, where they illuminate your keyboard and desktop (the real, physical one) but not the screen, not you, and not the wall behind you.  Softly illuminating the entire ceiling also works well.


How to Adjust Monitor Contrast and Brightness contrast brightness

Display an image which is mostly or entirely black (Such as this one) so it fills the screen.  Set the contrast control to the middle or higher.  Adjust the brightness so that the black background just becomes completely dark, with no general "glow".  Now display something with a range of brightness (Such as this).  Adjust the contrast to suit you.  On some monitors, the effects of the two controls may interact, requiring you to repeat these steps.


Image Viewer

An excellent, free image viewing program for Windows is IrfanView.

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Jeff Root
June 9, 2005