Graphics::Colourset is a Perl module to create sets of colours.
my $cs1 = Graphics::Colourset->new(hue=>60, shade=>1);
my $col_str = $cs1->as_hex_string('foreground');
my $cs2 = $cs1->new_alt_colourset(shade=>4);
my @colsets = $cs1->new_alt_coloursets(3);
This module generates the colour definitions of a set of colours suitable for using as the basis of a colour-scheme for an X-Windows window-manager. They can also be used for CSS colour descriptions for Web-pages. The colours are defined as the usual "hex string", or as the more recent "rgb string".
The aim of this is to avoid having to generate harmonious colour schemes by hand but to input a minimum number of parameters and to create all the colours from that.