Looking quickly at CPAN, it seems that you want Number::RGB. Looks like you can create an object using the hex notation and then grab the decimal RGB components.

Edit: If you'd prefer the do it yourself version, the function you want is hex. You can pop off each two-hex digit pair and then say $red = hex $first_match, etc.

Edit^2: Apparently Liverpole can code the DiY solution in the time it takes me to think up the DiY solution, hehe.