Filter panel is not showing in product page

Hi I have an ecommerce website that use opencart 1.5.5.1 and I need to display filters.

My steps so far :

1. Install Filter module
2. Add to category and product layouts on column left.
3. Go to catalog - filter, create a test filter group Colors with values 'black' and 'white'
4. Go to a category - date - filters -> add black
5. Go to a product - links - > add black

When I go to Frontend in category page the filter panel is there, but on a product page it doesn't display anything. What I'm missing ?