Web colors

Web colors are special colors used to show pictures and text on websites. They help make the internet look bright and clear.

Computers mix three main colors to make all others: red, green, and blue. By changing how bright or dim each of these colors is, we can create millions of different shades. This gives websites many colors to choose from.

Early web browsers like Mosaic and Netscape Navigator used a list of color names. Today, web colors follow a standard called sRGB. This helps colors look similar on most screens. Modern ways also give designers even more color choices.

Hex triplet

A hex triplet is a special six-digit (or eight-digit) number used to show colors on websites and in computer programs. It stands for the red, green, and blue parts of a color. Each part can range from 0 to 255, which is shown as a two-digit number in a special counting system called hexadecimal.

For example, a brown color might have red=123, green=58, and blue=30. In hexadecimal, these become 7B, 3A, and 1E. Putting them together gives the hex triplet 7B3A1E.

Sometimes, a shorter three-digit form is used, like 09C, which expands to 0099CC. This shorter way only gives 4,096 colors instead of the 16,777,216 colors possible with the full six-digit form.

HTML color names

HTML and XHTML let you use colors for text, backgrounds, and other things. There are two types of color names: basic and extended.

The basic colors are 16 colors set by the HTML 4.01 rules. These colors work well on most computers.

Extended colors come from mixing rules from HTML, CSS, and SVG. Many web browsers understand these colors. Some of these colors have different names but look the same, like "aqua" and "cyan," or "fuchsia" and "magenta."

CSS colors

The Cascading Style Sheets rules define colors that can be used on web pages. There are 16 basic color names that have been used since the early web. Later versions of CSS, like CSS3, added new ways to describe colors. You can now use colors described with numbers, such as a code that starts with a # symbol. There are also ways to describe colors using models like HSL, which stands for Hue, Saturation, and Lightness.

Web-safe colors

In the mid-1990s, many computer screens could only show 256 colors. When a color needed for a picture wasn't available, the computer had to pick a close color.

To help with this, a group of 216 colors was created. This number was chosen because it left space for computer systems to use other colors, and it allowed six shades of red, green, and blue. These colors were picked because they worked well with early web browsers.

Even though these "web-safe" colors were meant to show clearly, they sometimes still had to mix colors on certain computers. As better screens with more colors became common in the 2000s, the idea of web-safe colors was used less.

Each of these colors can be described using numbers for red, green, and blue. These numbers help computers know exactly which color to show.

The list of web-safe colors includes some that are easier to see clearly on old screens. These are called the "really safe palette."

Accessibility

Some browsers and devices cannot show colors. For people who cannot see colors or for those who are colorblind, websites that only use colors can be hard or impossible to use.

To help everyone, it is best to either not use colors at all or to choose colors carefully. This means picking colors for both the background and all text and links so that they are easy to see.

The Web Content Accessibility Guidelines suggest that text should stand out clearly from the background. For normal-sized text, the difference should be at least 4.5 times brighter or darker than the background. For larger text, the difference should be at least 3 times.