logging back in to answer this ! fashion color fades quickly so you will need to stay on top of maintenance if you want to maintain a dark, rich color. i buy multiple tubes of my preferred dye at once (nightfall from pulp riot). i have a stylist bleach my roots every 7 weeks or so but i touch up the dye myself at home every ~3 weeks. in an empty container, i mix some of the dye with a bunch of my favorite conditioner. that's what i use as conditioner when i shower to keep it vibrant. because my hair is bleached i don't wash it super often, once every 5-6 days or so, and i am very gentle with it - if i use shampoo at all i use a dye safe one, or i cowash. if you do what i do you will probably have slightly blue ears when the dye is fresh and sometimes even a blue forehead if you get really sweaty but that's the price i pay for dark blue. sometimes im sick of the maintenance and i think of dying it black again but i wanna keep this going for as long as possible against all odds bc i love it