Colors and Hexadecimal Values

When working on the Web, colors are specified using their hexadecimal values. The hexadecimal method of counting involves starting at 0 and continuing to f. The full counting range is 0 1 2 3 4 5 6 7 8 9 a b c d e f. Reach color in the RGB system is assigned a value based on this method of counting.

Thus, true red is coded as ff0000. The first two digits in the code represent the “amount” of red that is to be displayed. That amount is ff. The next two digits represent the amount of green, 00. The last two digits are for the quantity of blue, again 00. Thus, in true red, ff0000, there is ff amount of red, no green, and no blue.

The hexadecimal code for true green is 00ff00. True blue is 0000ff. Varying the amounts of red, green, and blue specifies other colors. 33CC99 is a particular shade of green, for instance. A complete browser safe color chart showing actual colors and their codes may be viewed by clicking here. The chart will open in a new window.

Interestingly, there are actual names for some of the browser safe colors. Rather that specifying the hexadecimal code in a Web page, it is possible to use these color names. Although 216 names exist, such as aquamarine, beige, and red, only 140 of them are reliable. Browsers do not recognize the entire list. In some instances, two or more names apply to the same color. The use of names is highly discouraged when building a Web page.

Browser safe colors

Web Color

What happens when a browser is asked to display a color that is not in it’s color pallet? There are two options. In some circumstances the browser may substitute a browser safe color for the new one. However, in other situations the browser attempts to compose the new color using several browser safe colors. In the case of a photograph, for instance, the results will be small dots all over a region that should actually look like a solid color. These dots will each be one of the several browser safe colors that make up the new color when viewed together.

This dotted effect is called “pixelation” because the dots are made up of pixels. It often resembles a pointillist painting.

The safest way to avoid pixelation is to use browser safe colors whenever possible. This is especially true for colors generated by HTML code, such as table background colors, and GIF images. GIF images are usually used for drawings and logos, both of which tend to feature masses of solid colors.

Colors that are not browser safe
If the colors in the box above do not appear on your
screen, try viewing it with another browser. Colors
that are not browser safe may not be displayed by
some browsers.