in html, colors are represented either as hexadecimal values ​​(such as #ff0000) or as color names (red). web-safe colors refer to the same colors displayed in netscape navigator and microsoft internet explorer, whether running in windows or macintosh systems, in 256-color mode. conventional rule of thumb is that there are 216 common colors, and any hex value that combines the 00, 33, 66, 99, cc, or ff pairs (the rgb values ​​are 0, 51, 102, 153, 204, and 255 respectively) represents web security color.

however, the test showed only 212 web-safe colors instead of all 216 because windows internet explorer does not correctly render colors #0033ff (0,51,255), #3300ff (51,0,255), #00ff33 (0,255,51), and # 33ff00 (51,255,0).

when web browsers first set up their appearance, most computers display only 265 colors (8-bit). today, most computers can display thousands or millions of colors (16-bit and 32-bit), so if you are developing a site for users of current computer systems, there is absolutely no need to use browser security adjustments. swatches.

one use case for using a web-safe color palette is when developing sites for alternative web devices, such as pdas and cell phone displays. many of these devices offer only black and white (1-bit) or 256-color (8-bit) displays.