use strict;

sub hex2rgb
{
    my $hex = shift;

    if (my @data = ($hex =~ /\#((?:[0-9a-fA-F]){2})((?:[0-9a-fA-F]){2})((?:[0-9a-fA-F]){2})/)) {
        return join(',', map({ hex($_); } @data));
    } else {
        die "Bad hex: ", $hex;
    }
}

print hex2rgb("#ff00ff"), "\n";
print hex2rgb("#fx00ff"), "\n";