The investigations on the effect of seed colouring on paddy and maize seeds encompassing 25 dyes were conducted to identify non-deleterious and deleterious dyes based on their effect on seed quality. The dyes namely Rhodamine-B, Fast green and Fuchsine in order of preference both for paddy and maize are the best dyes for seed colouring at 0.75% concentration.   In this paper the possibility of developing colour standards for paddy and maize seeds and their resultant implications for Indian seed industry has been discussed.