In 1994, 216 colours were defined by Netscape having a priority in browsers based on the 256 colours exhibited by an 8-bit system. However, 40 colours showed up differently between PCs and MACs and were therefore done away with.
These 216 fixed colours, also named web safe colours have been universally recognized by all browsers and operating systems. In other words, websites using these colours only are more likely to look similar on any browser.
Fewer than 5% of computer systems are at present using 8-bit systems and are consequently limited to 256 colours. Nevertheless, you should still make use of web safe colours to start off with, particularly for logos, flat colour illustrations, backgrounds, and large areas of an identical color in any picture.
Web colours are constructed around 3 pairs of hexadecimal digits. Each pair stands for a value from 3 root colors: red, green, and blue usually shown as RGB.
Hexadecimal is not based on 10 digits but 16. Therefore, A would be equal to 11, B to 12, and so forth. For example, 000000 is black, FFFFFF is white and FF0000 is red. The first pair of numbers show the amount of red, the second set represents how much green and the last set stand for how much blue is employed to get that particular colour. 00 represents no amount of that colour (0%) while FF is the most amount of any colour you could use (100%).
The percentage breakdown goes as follows:
0%=00, 20%=33, 40%=66, 60%=99, 80%=CC, 100%=FF.
Colours which are made up of 3 pairs of identical hexadecimal digits, or web safe colours, are composed of every combination of 00, 33, 66, 99, CC, and FF for each root colour (6 x 6 x 6 = 216).
Nowadays, computers aren’t limited anymore to the 256 colours shown by 8-bit video cards. 4096 colours are displayed on 16-bit cards (also called web smart colours), whereas 32-bit cards will show millions of various colours (known as unsafe colours). The complete number of possible colours goes beyond 16 million, because each root colour can be one of 256 values (256 x 256 x 256 = 16,777,216). As long as your video card will support it, your browser will be able to display any of these colours.
You can find many colour wheels and charts available on the net that will help you choose web safe, web smart, or unsafe colours. Find a few below:
216 web safe color charts can be found at: http://www.permadi.com/tutorial/websafecolor/
And also at: http://www.techbomb.com/websafe/
The 4096 Colour Wheel will give you the hexadecimal values for web safe, web smart, and unsafe colours together with various saturations of shades. This is available at: http://www.ficml.org/jemimap/style/color/wheel.html
The 4096 Colour Picker & Mixer shows you how different coloured texts can appear with matching coloured backgrounds by using the web smart colour palette. This is available at: http://www.webcolors.freeserve.co.uk/pick4096.htm
The DHTML Colour Wheel gives the hexadecimal codes for all 16,777,216 colours. It can be found at: http://www.geocities.com/~prof_al/examples/colorwheel.html
Another version of the same colour wheel can display your chosen colour on the entire page. You can find it at:
Despite the fact that modern browsers display beyond 16 million colours, any colour which is not web safe won’t display in the same way on different browsers. If you would like to make use of colours on your web pages from the web smart or unsafe colours choice, always double check your pages on all the different browsers. Doing this will ensure that your chosen colours look good to all the people visiting your website.
Martin Redford is contributing editor at WebDesignArticles.net. This article may be reproduced provided that its complete content, links and author byline are kept intact and unchanged. No additional links permitted. Hyperlinks and/or URLs must remain both human clickable and search engine spiderable.