I am using Magento 18.104.22.168 and would like to add on category page search by: color and other attributes, which I created. Price is there, but how to add others to search by?
For your requirements, you need to check this link : http://www.templatemonster.com/help/magento-how-to-create-an-attribute-and-apply-it-to-products.html
The attributes must be Multiselect or select in order for them to be filterable. When I want to convert them; I usually do it in the database.. There are extensions out that there that convert them.. but I have never personally used one so cannot recommend one.