Have you tried it like that?

#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper 'Dumper';

my @colors = qw( white yellow green );
my %hash;
$hash{ @colors } = @colors;

print Dumper \%hash;

__END__
[download]

I get this in perl 5.8.6:

$VAR1 = {
          '3' => 3
        };
[download]

Perl assumes you want to evaluate the array in scalar context. Better to stick to the same notation everyone else uses for hash slices.