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
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!
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.
An excellent, free image viewing program for Windows is
To my Space and Science home page
June 9, 2005