And of course, this approach allows a number to represent more than one color, if this is necessary:

c:\@Work\Perl\monks>perl -wMstrict -le
"my $color = 7;
 ;;
 my %colors = qw(blue 1  green 7  red 3  pink 7  purple 6);
 ;;
 my @picked = grep { $colors{$_} eq $color } keys %colors;
 print qq{color(s) picked by $color: @picked};
"
color(s) picked by 7: green pink
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