Here's a breakdown:
* Why it doesn't work as well on dark hair: Splat Washables are semi-permanent colors that coat the hair shaft. They don't lighten the hair. On dark hair, the existing dark pigments will overpower the semi-permanent dye, making the color appear muted or non-existent.
* Potential outcomes on dark hair:
* A slight tint (e.g., a barely noticeable red hue in direct sunlight)
* No visible color change at all.
* Ways to make it more visible (but still not guaranteed):
* Choose a color that's closer to your natural hair color: For example, a dark blue might be more noticeable than a light pink on dark hair.
* Apply liberally and leave it on for the maximum recommended time.
* Highlight or lighten a section of your hair first: This is the only way to guarantee a vibrant color result with Splat Washables on dark hair.
In conclusion: Splat Washables are generally not recommended for dark hair if you're looking for a vibrant, noticeable color change. You'll need to pre-lighten your hair for the color to truly show.