In site.css: .row_2 { background-color: #f4f4f4; } .row_1 { background-color: #ffffff; } In generate.pl: ... print "\@import url(/site.css);\n"; my $num_rowtypes = 2; ... my $count = 0; for(my $i=0;$i<=$#{$items_list};$i++) { print "