There are several ways for classification of dyes. It should be noted that each class of dye has a very unique chemistry, structure and particular way of bonding. While some dyes can react chemically with the substrates forming strong bonds in the process, others can be held by physical forces. Some of the prominent ways of classification is given hereunder.

• Organic/Inorganic
• Natural/Synthetic
• By area and method of application
• Chemical classification- Based on the nature of their respective chromophores.
• By nature of the Electronic Excitation (i.e, energy transfer colorants, absorption colorants and fluorescent colorants).
• According to the dyeing methods
  • Anionic (for Protein fiber)
  • Direct (Cellulose)
  • Disperse (Polyamide fibers)
• However the most popular classification is the one that is advocated by the US International Trade Commission. This system classifies dyes into 12 types.