How many different colours of LEGO bricks are there? Excluding translucent pieces, how many colours of official LEGO bricks are there?
The official LEGO color chart at Peeron has 111 colors listed. There are 14 listed as "transparent" (or "tr"), so - 97.

The Peeron guide also lists CMYK, RGB, HTML Hex Codes (displayed as the sample), and Pantone numbers for each.