How long will the colour stay and how can I slow down fading?

Because the pigment is not oxidised into the hair shaft, it stays on and around the outer layer and gradually washes out. The heavy pigment load helps the shade remain expressive for several washes, but there is no universal “lives for X washes” number, because fade speed depends on your hair's porosity, your washing habits, and the products you use.

If you want the neon tone to stay vivid longer, reduce how often you wash your hair. When you do wash, use lukewarm or cool water; hot water opens the cuticle and accelerates pigment loss. Choose a gentle, sulfate-free shampoo formulated for coloured hair where possible. Also rinse the balm out thoroughly after application so no excess pigment sits on the strands and fades unevenly.

Porous or bleached hair tends to hold direct pigments longer, and sometimes unevenly, so the colour can remain in patches after the rest fades. A strand test helps you predict this. When the tone starts to look washed out, you can refresh it with another application, which is the usual way this kind of semi-permanent product is used between salon visits.