It has been 6 months since I got my dry hair coloured. The reds are the worst as they fade the fastest. That is how Katrina Kaif managed to spend 55L on the Chinar-esque shade she got which I absolutely fell in love with. My red lasted for 3 months and since then my hair is chocolate brown which is not too bad if I can say so.
In the long run, I can also claim that my dry hair is doing pretty well after the intensive chemical treatment it went through. But, yes, the post coloured dry hair care is an intensive process. You can let it go for even a week. I do slip off quite a many times and make up for it by getting a hair spa! Anyways, let me share what I did and did not do which you should do.
How to take care of your post coloured dry hair?
Shampoo less but not too Less
I have noticed in the past one year that my hair behaves best when washed on alternate days. The more I go without washing, more hair falls. Find out the optimum time your hair behaves well without shampoo and stick to that. Two should be good if you have normal hair but three is good for both oily and dry hair.