Depending on the amount of WHITE hair you have leaves you several options. If your white hair is less than 5% then you could try using a STAINER or a coloured shampoo. ...More >
What I would do is visit a good professional salon in your area and get first hand advice.
After looking at your hair and the percentage of white hairs you have they will be able to advise you of your best options.
If you can stay away from permanent colour and use stainers or semi permanent colour this will have less impact on your wallet with maintenance and upkeep.