Colour transforms your hair — but it also changes its structure. Whether you’ve gone a few shades lighter or fully bleached, chemically treated hair is more fragile, more porous and more demanding to look after. The reward for caring for it well is twofold: stronger hair and a colour that stays bright for longer.
Here’s what colour and bleach do to your hair, and how to keep it strong.
What colour and bleach do to the hair fibre
To deposit or lift colour, the process has to open the hair’s outer layer — the cuticle — to reach inside the strand. Bleaching goes further, breaking down the natural pigment altogether. This leaves the cuticle raised and the fibre more porous: it loses moisture faster, tangles more easily, and is more prone to breakage. The more often hair is processed — and the lighter you go — the more pronounced this becomes. It’s the same fibre damage we cover in our guide on why hair breaks, concentrated by chemical processing. For the science of the fibre itself, see our trichology guide to hair shaft defects.
How to keep coloured and bleached hair strong
Wash gently, and not too often
Coloured hair does best with a gentle, colour-safe shampoo and a little less frequent washing — every wash gradually fades colour and challenges an already fragile fibre. Use lukewarm rather than hot water, which opens the cuticle and speeds colour loss. Our guide on how often to wash your hair can help you find the right rhythm.
Replenish moisture and strength
Because processed hair loses moisture and is structurally weaker, it benefits from regular restorative care — conditioning and restructuring treatments that smooth the cuticle, improve strength and reduce the look of split ends. This is exactly what fibre-focused care is designed to do.
Protect the colour from fading
Colour fades fastest with heat, sun and harsh washing. Limit high-heat styling, use heat protection, and shield hair from strong sun — UV lightens and dulls colour, which is why summer protection matters even more for coloured hair. Chlorine and salt water are also harsh on treated hair, so rinse after swimming.
Be gentle, especially when wet
Processed hair is most vulnerable when wet. Detangle softly with a wide-tooth comb from the ends upwards, avoid rough towel-drying, and don’t pull hair into tight styles while it’s fragile.
Space out your appointments
The more frequently hair is coloured or lightened, the less time it has to recover. Stretching the time between sessions — and keeping bleach to where it’s needed rather than re-processing the whole length — protects the fibre considerably.
A note on bleached hair
Bleached hair is the most demanding case of all. Because lightening breaks down pigment and significantly raises porosity, bleached hair needs the gentlest handling, the most consistent restorative care, and the most patience between sessions. If your hair feels gummy or stretchy when wet, or breaks very easily after bleaching, ease off further processing and focus on rebuilding the fibre’s condition first.
The right routine for coloured hair
A colour-safe approach combines a gentle cleansing shampoo formulated for coloured hair with regular fibre-restoring care. SIMONE TRICHOLOGY’s Bio-Repair, Moisture & Fibre Restructuring range is built to restore and protect treated hair — smoothing the cuticle, supporting strength and helping coloured hair stay in better condition between salon visits.
Want a routine matched to your hair?
Coloured and bleached hair varies enormously — how light you’ve gone, how often, your natural texture. Our online Hair Clinic offers a free, no-commitment pre-assessment: a few targeted questions about your hair, and personalised guidance on the routine that will keep yours strong and your colour looking its best.
SIMONE TRICHOLOGY products are cosmetic products and are not intended to diagnose, treat, cure or prevent any medical condition. If you have a persistent or severe scalp or hair condition, please consult a healthcare professional.
