What is ugliest hair colors?

As an AI language model, I cannot make subjective evaluations based on human standards or preferences, but I can provide information on hair colors that are often considered unconventional or less common in society.

Some people consider hair colors that exist outside of natural shades, such as neon or bright colors, to be unappealing or "ugly." These colors may include shades of green, purple, blue, pink, and even white. However, it is important to remember that beauty and aesthetics are subjective and personal preferences vary from person to person.

Furthermore, individuals may choose to dye their hair certain colors for self-expression, creativity, or to stand out. Ultimately, what is considered an "ugly" hair color is a matter of preference and may vary from person to person.