What is c40 eye color?

As an AI language model, I don't have access to any information about "c40" eye color as it doesn't make sense in the context of human genetics and biology. Eye color is determined by the amount and type of pigments in the iris, which is related to specific genes inherited from parents. The most common eye colors are brown, blue, green, and gray, with many variations and combinations. Eye color can also change over time due to various factors, such as age, health, and environmental factors.