How should I apply it for the best result, especially if my hair is light or porous?

Apply the shampoo to wet hair exactly as you would a regular shampoo: distribute evenly, lather well to spread the pigments through the lengths, and leave it on for the processing time indicated in the enclosed leaflet. The lathering texture helps cover short to medium hair evenly. After the time elapses, rinse thoroughly until water runs clear. On light blonde, bleached, highlighted, or porous hair, pigments deposit more strongly, so the ruby tone can become more intense than expected. To control depth, start with the minimum recommended time or even slightly less, check the result, and only increase time on subsequent uses if you want a deeper shade. A strand test 24 hours before full application is the safest way to preview the outcome on your specific hair. Avoid contact with eyes; if contact occurs, rinse immediately. If you have a sensitive scalp or have reacted to hair colourants before, do a patch test 48 hours prior and consider consulting a specialist before use.