Molly E. Holzschlag, Communications Director
World Organization of Webmasters
you practising safe color? Do you care? While the
challenge of interpretable color has been somewhat
ameliorated by the spread of better color-management
systems, achieving consistent color across computers,
platforms, and browsers is still very difficult, if
not downright impossible.
Why is this, and how do you decide whether to adhere
to Web-safe colors or toss the seemingly limited 216-color
palette out the window? Integrating your knowledge
of the way computers manage color, how the Web-safe
palette came to be, and why safe isn't really safe
will help you gain a deeper perspective on why Web
color is the way it is. You will also learn to aim
for the color results that best meet your needs.
Computer color technology
As if issues between code for differing browsers and
platforms weren't enough to keep ibuprofen manufacturers
in business, there's also the issue of interpretable
color. The problems with inconsistent Web color from
screen to screen are rooted in platform and browser
From a technical perspective, computers can display
a range of colors onscreen, depending upon the relationship
between a computer and the platform it's on and the
type of video memory available. This technology combined
with the computer screen layout (which is essentially
a grid made up of many small boxes - pixels) brings
your Web designs to the screen.
To achieve color in the digital world, light stimulus
must be added to other light. This process is referred
to as additive synthesis. In this model, the primary
colors are red, green, and blue.
A perfect example of additive synthesis is your television
screen. When you look at the picture on a TV screen,
you're really looking at thousands of phosphor dots
made up of red, green, and blue. The dots are tiny,
so they appear to blend together to achieve a given
color. RGB computer monitors work the same way.
Additive color originates within an algorithm that
numerically determines how much of a given light stimulus
makes up the color in question. Each color available
on a computer contains some percentage of red, green,
or blue. So when I'm using a computer, I can mix a
bit of red light, a bit of blue light, and a bit of
green light and come up with yellow light.
Specifically, secondary colors in the additive process
are created using the same ratio found in subtractive
synthesis. If I mix one part of red with one part
of blue, I get a secondary color (in this case, magenta).
The absence of light stimulus makes black, and equal
portions of red, blue, and green make white. To render
color onscreen, computer color-management systems
allot each available pixel a specific amount of a
computer's video memory in bits. The type and quality
of color changes depending on the number of bits and
1. Early computer color, one bit per pixel,
two colors total
Lowest on the totem pole
when it comes to color management onscreen is
one bit per pixel. This supports only two colors
(see Figure 1). One-bit systems were common
once upon a time, but now they're almost unheard
of (especially for home computer users), and
most certainly for Web designers and developers.
It's possible that designers will have to think
about 1-bit color again as more cell-phones
and PDAs are connected to the Internet.
The next color level is known as 8-bit color. When
8 bits of color are allotted to a single pixel,
the resulting number of possible colors is 256.
As you know, this is an important number when it
comes to Web color. For the moment, it suffices
to say that 256-color systems are in popular use.
But again, the proliferation of higher-end systems
for home users, as well as the speciality systems
used by designers, make 8-bit color systems less
important as time goes on?at least in terms of how
Web color is produced.
Sixteen-bit color appears in systems that allot
16 bits of video RAM to a pixel. The resulting number
of colors is in the thousands, which naturally offers
a radical increase in color quality. But interestingly
enough, the 16-bit color model is very different
from both the 256-color system below it, and the
systems with millions of colors above it. This is
due to the fact that 16-bit color, also referred
to as high color, is based on a system of percentages.
As a result, the colors in high color may or may
not have crossover colors from either the lower
or higher ends of color management.
Finally, true color monitors are those capable of
managing 24 bits of RAM per pixel. This, in turn,
creates millions - specifically 16,777,216 - of
resulting colors. It's important to point out that
this palette is more mathematically in step with
the methods by which the 256-color systems work.
As a result, all 256 colors in the 8-bit system
are also found in the 24-bit system.
Color for browsers
No doubt you're intimate with the Web-safe (also
known as browser-safe) palette. This palette consists
of 216 colors that should remain stable across Mac
and Windows platforms. In reality, you'll never
get consistent color across browsers and platforms
(there are simply too many variables). However,
it's extremely important to reach for the most consistency,
and that's exactly why Web-safe color evolved.
But if color systems can support at least 256 colors
and at best millions of colors, why is the Web-safe
palette so limited? It's a historical issue, and
one that I'll describe here to emphasize that using
this palette is important, but not always necessary.
color on the left is Macintosh color
and on the right is Windows color
the Web became a visual space in 1994, most Macintosh
and Windows computers were 8-bit, 256-color. Each
platform reserves about 20 colors for use by the
system, and there are differences between the color
tables found on those platforms. All told, in an
8-bit system, the differences total 40 varying colors
(see Figure 2 above). If a designer uses an unsupported
color, the potential for dithering is high in 8-bit
systems (the computer will pick the closest possible
color). Other problems include grabbing a different
color completely, so a light pastel pink might suddenly
become neon pink on another system. This inconsistency
is, for obvious reasons, problematic.
To reduce the cross-browser, cross-platform inconsistencies,
Netscape eliminated the 40 problematic colors and
created a browser-specific palette of 216 colors.
Ideally, using these colors reduces dithering and
other color rendering problems across platforms.
As a result, the Web-safe palette was born.
Now that computers support 16 and 24-bit color,
the browser-safe color issue becomes less of a concern
in certain circumstances. However, many designers
have stuck to the browser-safe palette because there
are still many computers (particularly those in
schools, countries outside the U.S., and other areas)
that are limited to 256 colors. If you use the Web-safe
palette, you're likely to achieve greater consistency
with your designs.
But all is not perfect in the so-called Web-safe
world. Why not? Well, consider the earlier discussion
describing the differences between 16-bit and 24-bit
systems. Your colors might appear slightly different
on a 16-bit system and a 24-bit system, even if
you're using the Web-safe palette. What's more,
several concerned parties began to closely examine
the emerging problems with Web-safe colors. They
found some disconcerting evidence that what we think
is Web-safe really isn't safe at all.
3. Possibly the only truly Web-safe colors
Web designers complain all the time about the
incredible restrictions that the Web-safe palette
imposes, and they often choose not to use any
colors from it. Of course, there's a devil's
advocate point of view here: Many print designers
who move to the Web get excited that they can
use so much color for free. Color processing
in print is expensive. On the Web, it's not.
So some designers feel empowered to be able
to use color at all.
However, consider these startling revelations.
In January 1999, Bob Stein of VisiBone (www.visibone.com)
performed some tests across monitors. His results
suggest that there are only 125 truly Web-safe
colors from which to choose. Stein does point
out that some of the problem might be caused
by the hardware, and some of it might be related
A later test, performed by David Lehn and Hadley
Stern for WebMonkey in September 2000, looked
at colors across system types, browser types,
and computer types and ended up with only 22
colors that could be considered truly Web-safe
(see Figure 3 on the left). These colors are
very limiting and not the most attractive!
Yet, none of this answers the question of whether
a Web designer should use the Web-safe palette.
In the everyday world, many designers don't
even adhere to the 216-color palette, much less
the subtler concerns of even more limited palettes
for true cross-platform, cross-browser color
Aside from tossing up your hands in utter despair,
there are two routes you can take regarding
Web-safe color: Stick to the 216-color palette
at all times; or forget the palette and use
any color you want. Depending upon your circumstances,
either of these choices can be viewed as wise
you know the types of computers, browsers, and
monitors that the majority of your audience
uses, you have much more flexibility in terms
of color choice. A good example of this is in
Intranet applications. If most people access
your pages with high-end browsers and monitors,
you can work outside of the Web-safe palette.
However, if you have a global audience, or one
that uses computers of considerably varying
quality, sticking to the Web-safe palette is
The laughable fact is that even if you're extremely
careful and use the 216-color palette, the variations
among platforms, browsers, and monitor types will
still render your colors inconsistent. To use it,
or not? Weigh the knowledge you've gathered here with
your awareness of your audience, and choose the lesser
evil. Whether your audience will know the difference
is the real question.
Reviewed at AbleStable®
Style Sheets: The Designer's Edge by Molly E.