use strict;
use warnings;


my %sets;

while( <DATA> ) {
    chomp;
    next unless length;
    my( $entry, $color ) = split /\s+/;
    push @{$sets{$entry}}, $color;
}


foreach my $entry ( keys %sets ) {
    print $entry;
    foreach my $color ( @{$sets{$entry}} ) {
        print "\t$color\n";
    }
}


__DATA__
John     red
Mike     yellow
Peter    white
Peter    brown
Jim      purple
Antony   orange
Antony   green
George   black