It is best to use Web-safe colors for HTML; otherwise you could run into browser palette issues.
For Web-safe colors that are rendered the same by all browsers, use color numbers 1 through 8, or define colors with elements of 00, 33, 66, 99, CC, or FF For example, RGB hexadecimal value 0099CC yields the color shown in Figure 22-1.
Table 22-1 lists the values you can use to define Web-safe RGB colors, in three different units of measurement.