Hot roots

Hot roots is a term used in the context of hair dyeing, specifically when dyeing hair a lighter color than its natural shade or previously dyed shade. It refers to a phenomenon where the roots of the hair process faster and become significantly lighter or brighter in color than the rest of the hair shaft during the dyeing process.

This occurs due to several factors:

• Heat: The scalp naturally emits heat, which accelerates the chemical reactions of the hair dye. The hair closest to the scalp (the roots) is therefore exposed to more heat than the rest of the hair.
• Virgin Hair: The roots often consist of newly grown, undyed ("virgin") hair. This hair is more porous and readily accepts dye compared to hair that has been previously treated with color or other chemicals.
• Proximity: The proximity of the dye to the scalp allows for the dye to penetrate the hair follicle more effectively than if it was further away.

The result is that the roots appear disproportionately lighter, brighter, or even orange-toned compared to the mid-lengths and ends of the hair, creating a noticeable and often undesirable contrast.

Techniques to prevent or correct hot roots include:

• Starting Application Away From the Roots: Applying the dye to the mid-lengths and ends of the hair first, allowing it to process for a certain amount of time, and then applying the dye to the roots last. This ensures that the roots are exposed to the dye for a shorter duration.
• Using a Lower Volume Developer at the Roots: A lower volume developer causes less lift and can help to control the processing speed at the roots.
• Root Smudging/Shadow Root: Purposefully creating a darker root area to blend with the rest of the hair and avoid a harsh line of demarcation.
• Cool-Toned Toners: Using toners to neutralize unwanted warmth or brassiness at the roots.