The 7 Common Mistakes (and Fixes)
- Skipping a strand test
- Always test 5–10 minutes on a hidden piece to check tone and timing.
- Wrong undertone (violet vs. blue)
- Use violet for yellow and blue for orange brass (cool brunettes often need blue).
- Masks & maintenance hub: https://kostumeusa.store/color-maintenance-hair-care/
- Applying over heavy buildup
- If hair feels coated or chalky, clarify first so pigment grabs evenly.
- Clarifying/detox shampoos: https://kostumeusa.store/product/best-repair-shampoo-restruturador/
- Over-processing time
- Most masks work in 5–15 minutes. Start shorter on porous ends.
- Skipping the seal
- After rinsing, use a leave-in to shield UV/heat and a serum to smooth the cuticle.
- Leave-in (12-in-1): https://kostumeusa.store/product/hair-treatment-purifier-micelar-leave-in-spray-12-in-1/
Serum: https://kostumeusa.store/product/k-fiber-reparador-essencial-hair-serum/
- Washing too often / water too hot
- Limit to 2–3 washes/week; lukewarm cleanse + cool rinse to reduce fade.
- Ignoring repair & hydration
- Color pops on healthy hair—condition regularly and add periodic bond/repair care.
- K. Fiber Repair Conditioner: https://kostumeusa.store/product/k-fiber-mascara-restruturador-best-repair-conditioner/
SOS Repair System (bond support): https://kostumeusa.store/product/sos-repair-system/
Simple Routine (Copy/Paste)
Clarify → Mask 10 min → Cool Rinse → Leave-In → Serum → Repair 1–2×/week.
Avoid the pitfalls—shop Masks, Leave-In, Serum, and Repair from the links above.

