Hair dyes are used by most adult women, so you can easily find them in pharmacies, such as San Pablo or Farmapronto, and also in perfumeries such as Comercial Mexicana, or Soriana, among others. You can also find them in commercial shops such as Liverpool.
On the internet you can also find a variety and assortment of hair dyes, through sites such as Amazon, Ebay, Linio and Mercado Libre, among others. The online system also gives you the additional benefit of being able to shop from home, where you can also receive your order.