The traditional color of the janeu is usually white or yellow, so a "Yellow Cotton Janeu" refers to a sacred thread made of yellow-colored cotton. As mentioned before, the janeu is a sacred thread worn by some upper-caste males in Hinduism as a symbol of their initiation into the religious and spiritual aspects of life.

The color yellow is considered auspicious in Hinduism and is often associated with purity, knowledge, and spiritual growth. It represents the illumination of the mind and the pursuit of wisdom.

Cotton is a commonly used material for making janeu threads due to its comfort, affordability, and availability. It is spun into a thick thread known as "mota dhaga" to create the janeu.

Wearing a yellow cotton janeu is a personal choice and can vary based on individual preferences and cultural practices. Its important to note that cultural traditions and customs can vary across different regions and communities, so there might be slight variations in the materials, colors, and styles of the janeu.