CGI Variables

[The Hobo]

I'm trying to alternate between using two colors in a Perl/CGI script as follows:

#declaration:
$color1 = "#1d91c9";
$color2 = "#d4d4d4";
$color = $color1;

#code to change:
if ($color == $color1) {
  $color = $color2;
} else {
  $color = $color1;
}

I've also tried = instead of == (can't remember what each is used for). It's been awhile since I've worked with cgi. Any ideas?