The synthesis of 4,5‐, 4,6‐, 4,7‐ and 5,7‐dichloro‐2‐aminobenzothiazoles is reported. Diazotisation of these and coupling to N‐substituted anilines affords orange‐red to blue dyes which have excellent coloration and good light fastness properties on polyester. The colour of the dyes is discussed with respect to the orientation of the chloro substituents and compared also with dichloro‐4‐aminoazobenzene analogues and to established colorants based on 5,6(6,7)‐dichloro