I've been dying my hair red for years and have recently decided to let it go natural (dark brown). So I dyed my brassy red hair a pretty dark brown from a box and really liked the results, only to find that - surprise, surprise - with every wash it gets much lighter and much reder (even though it was a "permanent dye"). A friend told me that is always going to happen when one tries to dye red hair something else. So now I'm considering going to a colorist and having my hair stripped and then dyed dark. So my question is whether this will work; i.e. will the red be sufficiently lifted out, and if it is, how often will I have to darken in so that it doesn't lighten to that weird, yellowish bleach color?