What's the best way maintain hair coloring?

I am dying my hair a semi-permanent midnight blue in a few weeks and I wanted to know how to maintain the color. I usually wash my hair once a week and most hairstyles I do on my hair require water. If I style my hair with water, I feel like the color will fade quicker.

2 Answers

Hm. These are probably good questions for a stylist. The fact that it's semi-permanent means that it won't last.... it's designed to wash out gradually. Avoid harsh sulfates and avoid products with glycerin. 
use a sulfate free shampoo