my $regex = join '|', qw( red green blue );
foreach my $line ( @lines ) {
    next if $line !~ $regex;
}

##</code><code>##

my $negative_regex = join '|', qw( red blue );
my $positive_regex = join '|', qw( green );
foreach my $line ( @lines ) {
    next if $line =~ $positive_regex || $line !~ $negative_regex;
}