i think the reason why we talkin colours is becasue, really the cossies in the early days were probably the only car to offer the kind of performance upgrades that we see even now, and there were also not as many different types/ manufactures of injectors, so bosch ones were used as they were a direct replacement fit and each flow rate came in different colours - look at almost any new style injecotr and they are predominantly black and so can be told apart unless you know the part number, counds better aswell , ive got greens rather than ive got Bosch 0-280-150-803

Stand yellow/blue 311cc/min 30.5 lb/hr
803 Greens 382cc/min 37.45 lb/hr
400 light blue 437cc/min 42.84 lb/hr
403 Grey 503cc/min 49.31 lb/hr