In the context of tattooing, what signifies the term "indelible"?

The term "indelible" in the context of tattooing signifies a permanent mark. This is important as it reflects the very nature of tattoos, which involve injecting ink into the skin to create designs that last for a long time, often for life. Indelible tattoos are designed to withstand time and external factors, thereby maintaining their appearance and meaning over the years.

In contrast to this, the other options describe characteristics that are not in line with what being indelible represents. A temporary effect refers to something that can be easily removed or fades away after a short time, while a fading design implies that the tattoo may lose its vibrancy or clarity over time, thus not being truly permanent. Washable color indicates that the color can be wiped away easily, which is the opposite of what indelible signifies. Hence, the concept of "indelible" is directly aligned with the permanence and lasting nature of tattoos, making it the correct answer.