By mixing red, green and blue light additively (see page 190), today’s computer monitor can display millions of different colours. This was not always the case: a few years ago, many computers could sometime be rendered incorrectly by a Web browser. Mac and Windows systems each had their own standard palette of 256 colours, but they were not the same. This gave rise to the 216-color ‘Web-safe’ palette, consisting of colours that ought to appear correctly on both Macs and PCs. With the demise of 8-bit (256 colour) monitors, the web-safe palette became largely obsolete-although the idea is now relevant to some designers again thanks to the less capable colour screen fitted to mobile devices, such as phones and PDAs, which include basic Web browsing facilities