my @paths = (
    "/colours/paprika/1/good/red",
    "/colours/paprika/1/bad/green",
    "/colours/paprika/2/good/yellow",
    "/colours/paprika/2/bad/brown",
    "/colours/banana/yellow"
);
my %invert = (
    colours=>[0,1,2,3,4],
    paprika=>[0,1,2,3],
    banana=>[4],
    good=>[0,2],
    bad=>[1,3],
    red=>[0],
    green=>[1],
    yellow=>[2,4],
    brown=>[3],
);