Hi peeps,
I have a hairdresser that works for me and apparently once per month is too much, you must see my hairdresser's hair from doing it on herself too often, it looks awful. Hair dye is only to be used once every 6-8 weeks and then only on the roots. Every 6 months the colour can be combed through the hair and left on for 10-15 minutes as Tilly ann mentioned. If you choose a good quality non fading home kit your colour on the rest of your hair shouldn't fade and then doing the roots is all it'll need.
I suppose this is like doing your own nails with an argos nails kit. Please consult a professional before coulouring your hair more often than what you need to. It gives the recommended every 6 weeks on the box for a good reason!
xxxx