BLOND STUDIO nutri-developer 40 vol 1000 gr BLOND STUDIO nutri-developer 40 vol 1000 gr is a professional-grade hair color developer that is formulated with a unique blend of keratin and argan oil to protect and nourish the hair during the coloring process. The formula provides intense conditioning and nourishment, while offering maximum lift and coverage to create the desired color. It is designed to be mixed with any BLOND STUDIO color cream for optimal results