eval {} is your friend :)

#!/usr/bin/perl

# http://perlmonks.org/?node_id=1201508

use strict;
use warnings;

my @colors = qw( red green nosuchcolor blue );
my $defaultcolor = 'black';

use Tk;

my $mw = MainWindow->new;

for my $color ( @colors )
  {
  eval
    {
    $mw->Label( -text => $color, -fg => $color )->pack;
    1;
    } //
    $mw->Label( -text => $color, -fg => $defaultcolor )->pack;
  }
MainLoop;
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