Hi, ive done many home job dyes- the dye you used probably contained some peroxide, hair at the root it fresh,warm (virgin hair its called), so it will take a hair dye well, the middle parts are not so fresh, and the ends are dead hair, which also may have had some previous dye on, so its very hard to get an even colour right away. the only way ive ever got it right is persistance- firstly- what length is your hair? what colour did you put on recently? what colour did you put on two years ago? and finally what condition is your hair in- prior to this last dye job, greasy,normal,dry? split ends?
once you tell me that i may be able to help.