Color is the main striking feature that enhances the appeal and acceptability of any fabric. Hence to make the commodity attractive a lot of natural and synthetic colors are used from time immemorial. These days, dyes of natural origin are gaining more popularity due to consumer awareness regarding the ill effects of synthetic dyes. Azo colorants, the significant portion of the dyes used in textile production aroused concerns on possible health impacts like potential carcinogenic and allergic properties (2). Hence directive 2002/61/EC amending 76/769/EEC restricts use of certain azo colorants and further amendments banned use of allergic disperse dyes, flame retardants (PDB, Penta BDE, TRIS, TEPA), phthalate softeners (DEHP, DBP, BBP) and many more from eco-labeling. These lead to a growing demand of bio-colorants or natural dyes in developed as well as emerging economies (1, 7). In the essence, the message of "Natural is better" is gaining popular day by day replacing the synthetic dyes (3-7).
Bio-colorants obtain mainly from natural sources, majority of plant origin and some from invertebrates. In addition of imparting unique color shades, natural dyes also provide wrinkle free, stain resistant, flame-retardant, anti-fungal, anti-bacterial, anti-static, odor resistant, and U.V. protective finishes to fabric.