Final answer:
The claim that gun-metal gray hair is ready to receive color is false; gray and white hair reacts differently and may not absorb semi-permanent hair color as effectively as pigmented hair.
Step-by-step explanation:
The statement that hair looking gun-metal gray is ready to receive color is false. Hair color is determined by the presence of melanin and gray or white hair has lost most of its melanin, which makes these hairs react differently to hair dyes compared to pigmented hair. In the case of semi-permanent hair color, it gradually washes out over four to six weeks and is less harsh than permanent dye. However, it has limitations when it comes to gray and white hair. Gray and white hair can be resistant to semi-permanent dyes and may not absorb the color at all, leading to inconsistent coloring. But using semi-permanent dye as a base with permanent highlights can help transition to 100% permanent color more gradually.