* Melanin Loss and Porosity: Grey hair lacks melanin, the pigment that gives hair its color. This makes it more porous than pigmented hair, meaning it has more open cuticles. Relaxers can further open the cuticle layer.
* Relaxer Formulation and Residue: Relaxers contain chemicals (usually alkaline) to break down the hair's bonds. Sometimes, residues from these chemicals, even after rinsing, can remain in the porous grey hair.
* Oxidation and Environmental Factors: When the alkaline residue from the relaxer reacts with air (oxidation) and environmental factors (like pollution, hard water minerals, or even certain hair products), it can cause a yellow or brassy tint. This is similar to how white fabrics can yellow over time.
* Sebum and Product Buildup: The scalp produces sebum (natural oil). In grey hair, sebum and product buildup can sometimes accumulate more easily due to the hair's texture and porosity. This buildup can also oxidize and contribute to a yellowish hue, especially when mixed with relaxer residue.
In summary, the combination of melanin loss, increased porosity, relaxer residue, oxidation, and potential buildup makes grey hair more susceptible to yellowing after a relaxer treatment.
How to Prevent or Correct It:
* Proper Neutralization: Ensure the relaxer is neutralized thoroughly after processing. Use a neutralizing shampoo multiple times until the water runs completely clear.
* Chelating Shampoo: Use a chelating shampoo to remove mineral buildup before and after relaxing.
* Protein Treatment: A protein treatment can help to fill in the porosity of the hair and make it less susceptible to absorbing unwanted color.
* Toner or Color Correction: A professional can use a toner or color-correcting product to neutralize the yellow tones. Purple or blue-toned shampoos can also help maintain the desired color.
* Use Gentle or Mild Relaxers: Consider relaxers formulated for sensitive or color-treated hair, as they might be less harsh.
* Consult a Professional: If you're unsure, have the relaxer applied by a stylist experienced with relaxing grey hair.
* Clarifying Shampoos: Use a clarifying shampoo periodically to remove buildup.
* Avoid Hard Water: If you have hard water, consider installing a shower filter.
* Protective Products: Use hair products designed to protect against environmental damage and UV rays.
By understanding these factors and taking preventative measures, you can help minimize the risk of grey hair turning yellow after a relaxer treatment.