This conditioner is designed to give a natural looking boost to a large range of red shades, ranging from the more coppery auburn to deeper burgundy-red shades by depositing key red tones. This red boosting formula can be used on multiple tones of red (copper to burgundy) but is not recommended for the lightest shades of hair (i.e. blonde, lightest auburn, grey etc) or the darkest shades of hair for optimal results.