sub random_color {
    my ($r, $g, $b) = (int(rand(256)), int(rand(256)), int(rand(256)));
    my $color1 = sprintf("#%02x%02x%02x", $r, $g, $b);
    my $color2 = sprintf("#%02x%02x%02x", ($r + 128) % 256, ($g + 128) % 256, ($b + 128) % 256);
    return ($color1, $color2);
}