Let WordPress Different Category Shows Different Style

For example, we are designing a company site using wordpress, 2 categoris: product category, and new category. How to let these 2 categories show different styles?

Creat 2 php files: product.php, news.php, and copy all contents from wp-content/themes/zeecompany/archive.php;
Edit wp-content/themes/zeecompany/archive.php, delete all contents in archive.php, and copy the following code in archive.php:

if ( is_category(1) ) {
include(TEMPLATEPATH . ‘/product.php’);
} else {
include(TEMPLATEPATH . ‘/news.php’);

Modify product.php, and news.php to let them show different styles as you need.