Pre-blended, permanent dark red-violet brown (4RV) that’s part of the SoColor permanent cream range Delivers vibrant red-violet tones that pop even on darker base levels; excellent gray coverage Infused with Bond-Protecting Concentrate for long-lasting color and hair integrity, color after color Application Info (Standard for SoColor Permanent Cream): Mixing ratio: 1:1 with Matrix Cream Developer (20 Vol standard) Processing time: 30–45 minutes (45 minutes for resistant gray hair)