This slider changes the hair color.

Good results are achieved with weights from -3 (light hair color) to 3 (dark hair color). Higher or lower weights are possible, but depending on the prompt used, it may look unnatural. If the prompt describes a dark hair color (e.g., dark purple, dark brown), then a weight of 3 is too high. To achieve a 100% consistent face, you should also use a character LoRA.