This page also has the 216 Netscape-safe color palette, but it uses a Javascript function to generate the table. I didn't write it myself. I came across it and modified it a bit. I'd give credit, but there was no author information available.
216 colors = (6 reds x 6 greens x 6 blues)
Decimal values for each color are 0, 51, 102, 153, 204, 255
Hexadecimal values are 00, 33, 66, 99, CC, FF