This will return 'grey' if you use a severity not defined in the hash: 
my %bkcolor = (
    'Extreme'  => 'red',
    'Severe'   => 'orange',
    'Moderate' => 'yellow',
    'Minor'    => 'green',
);

my $background = $bkcolor{$severity} // 'grey';

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In reply to Re: Replacing If Elsif Else with Hash by frozenwithjoy
in thread Replacing If Elsif Else with Hash by johnfl68

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