The Schwarzkopf Igora Royal Developer is specially formulated to be used with the Igora Royal Permanent Hair Color, ensuring exceptional color results. Available in 3%/10 Volume, 6%/20 Volume, 9%/30 Volume, and 12%/40 Volume, it allows for a variety of coloring needs. 3% / 10 Volume Ideal for darkening hair. Suitable for creating pastel tones (using 9.5-shades) on previously lightened or highlighted hair. 6% / 20 Volume Perfect for tone-on-tone coloring or lifting hair by 1 level, including white hair coverage when using shades from the Color of Rhapsody, Harmony, Lust, Perfection, and Serenity collections. Note: For the -00 shades within the Color of Serenity, always opt for the 9%/30 Vol. 9% / 30 Volume Achieve 1-2 levels of lift with shades from the Color of Rhapsody, Harmony, Lust, Perfection, and Serenity. Lighten hair by 2-3 levels when using 10-series shades. Lift 3-4 levels with 12-series shades. Provides excellent coverage for resistant white hair with “00” shades and white hair coverage with the Color of Commitment. 12% / 40 Volume Lightens hair by 2-3 levels with shades from the Color of Rhapsody, Harmony, Lust, Perfection, and Serenity. Lifts 3-4 levels with 10-series, with a natural base recommendation of 7-0 or lighter. Lightens by 4-5 levels when using 12-series, recommended for natural bases of 6-0 and lighter. This range ensures you can find the right developer strength for your specific hair color goals.