Why aren't Celts considered white?

In ancient Europe, Celts were regarded as an independent nation. Celtic people lived in Europe from 5th century BC to/kloc-0th century, and their ancestral homes were in Ireland, Scotland, Wales, England and France. However, in ancient Europe, the Celts were not considered white, but a people who lived in Europe from the 5th century BC to the 1 century. Their ancestral home is in today's Ireland, Scotland, Wales, England, France and other regions. But in ancient Europe, Celts were not considered white, and the color classification of ancient Europeans was not exactly the same as that of modern races. In ancient Europe, Celts were regarded as an independent nation, and their language, culture and traditions were different from those of neighboring Rome, Greece, Germanic and other nations. Celtic skin color is usually dark.