If your hair is porous, previously lightened, or chemically processed, the shade may develop more vividly. This means the pink could appear more intense or brighter than on virgin hair. It can also be less predictable, because porous hair absorbs color faster and may hold it differently. An even base matters for a balanced result, so if your hair has uneven lightening or damage, the color may look patchy.
Before you apply the dye, do a strand test. This is especially important if your hair is already lightened or damaged. A strand test will show you exactly how the color develops on your hair and whether you like the result. It also helps you avoid surprises. If your hair is very damaged, highly bleached, or your scalp is sensitive, do a skin sensitivity test as well. This product is for coloring, not for scalp conditioning, so extra attention to hair condition before and after use is sensible.
If your hair is in poor condition, consider whether the color is the right step right now. Permanent dye can add more stress to already fragile hair. If you decide to go ahead, use a deep conditioning treatment before and after coloring, and avoid overlapping the dye on already colored lengths to prevent over-processing.