216color

216color, also known as the "web-safe color palette," refers to a set of 216 colors that were designed to be displayed consistently across different computer monitors and operating systems. This palette emerged during the early days of the World Wide Web when screen color capabilities were limited, often to 256 colors. The goal was to ensure that web designers could choose colors that would render predictably for the widest possible audience.

The 216color palette is constructed using a limited set of red, green, and blue (RGB) values. Specifically, each primary color component can only have one of six possible values: 0, 51, 102, 153, 204, or 255. By combining these six levels for each of the three primary colors, one arrives at 6 x 6 x 6 = 216 unique color combinations. This systematic approach ensured a predictable and repeatable set of colors.

While the 216color palette was once a crucial consideration for web design, its relevance has significantly diminished with advancements in display technology. Modern monitors typically support millions of colors, making the concept of a "web-safe" palette largely obsolete. However, understanding 216color can still provide historical context for the evolution of web graphics and color management. Some legacy systems or specific design constraints might still benefit from its predictable nature, though it is rarely a primary concern for contemporary web development.