What do the different coloured lines mean, on the prop shaft??

[ADY1983]

Hi, Ok i have now got the old Engine out today and the prop shafts look the same but, the lines are different colours. I was told these do make a difference anyone know what???

 

[Doodle]

Could well be alignment marks, to make sure that it goes back together correctly. The prop on the Alfa certainly has some, and I shall shortly have to make good use of them, as the damn thing needs rebalancing.