I have always had trouble with natural shampoos, they have never agreed with me. This is better than many leaving my hair feeling cleaner, but still with a bit of an 'itch' factor. I couldn't use this every time I shampooed as my hair would feel too greasy and would lack shine, so I fit it in now and again to hopefully prolong my colour!
I use Logona Hair Dye Powder, and use this shampoo and 'Logona Natural Colour Conditioner' to help preserve the colour. It works, and feels nice too. I have washed my hair with 'normal' shampoo & conditioner whilst travelling, and this made the colour fade much more quickly. Shampoo is in 250ml bottles, and conditioner in 150ml, so you need approximately 2 conditioners per each bottle of shampoo.