use strict;
use warnings;

my %colours = (
    'baby blue'    => 'BB',
    'baby pink'    => 'BP',
    'dark blue'    => 'DB',
    'dark purple'  => 'DP',
    'hot pink'     => 'HP',
    'light purple' => 'LP',
    'pink' => 'PK',
    'pinkish' => 'PI',
);
my $colourMatch = join '|',
    sort {length $b <=> length $a || $a cmp $b} keys %colours;

for my $colour ('baby blue', 'baby pink', 'baby green', 'pink', 'pinkish') {
    if ($colour =~ /($colourMatch)/) {
        print "Matched $colour: $colours{$1}\n";
    } else {
        print "Unmatched: $colour\n";
    }
}