During a retouch procedure for a lighter result, the mixture should be applied to?

When performing a retouch procedure aimed at achieving a lighter result, the mixture should specifically be applied to the new growth area only. This is essential because the new growth represents the hair that has not been previously processed or colored. By applying the lighter mixture to this section, you ensure that the newly grown hair is treated effectively, allowing it to match the previously colored hair without over-processing the already treated strands.

Applying the mixture to the entire head or the ends could lead to uneven coloring and may damage the hair unnecessarily. The ends of the hair are already processed and could become over-lightened, leading to dryness or damage. Similarly, focusing on split ends without addressing the new growth would not achieve the desired uniformity in color, as it disregards the primary goal of the retouch procedure, which is to refresh and lighten the new growth at the roots. Thus, applying the mixture only to the new growth area optimizes the results while minimizing potential damage to the hair.