Enzymes have been widely used in the textile wet processing. The precise reaction specificity of an enzyme has been utilised for specific or targeted textile finishing without causing undesirable fibre damage. Laccases are important enzymes for their application in textile processing due to their great versatility and capability of catalysing the oxidation of a broad range of substrates. The investigation of laccase-catalysed coloration towards either wool or polyethylenimine was carried out. It is understood that amino groups from wool and polyethylenimine are involved in the formation of polymeric colour during laccase catalysation of catechin and gallic acid. The colour depth and shrink-resistance of wool can be improved significantly by incorporating a multi-primary amine compound, such as polyethylenimine, and a crosslinking agent, such as glycerol diglycidyl ether, in the enzymatic coloration process of wool. This demonstrated the potential to achieve combined coloration and shrink-resistant finishing for wool fabrics.