Caste

What does Caste mean?

Describes the shading or tone on denim.  Indigo denim can have a black, brown, gray, green, red, or yellow caste to it.

Heddels explains Caste 

The caste of a pair of jeans refers to any extra color tones that may be present in the fabric, sometimes added through an additional dyeing process.

For example, “greencast” denim, with a turquoise/greenish tint, is dyed in a green sulfur bath before being dyed with indigo. On the other hand, “redcast” denim, with an almost purplish tint, is denim that has only been dyed with pure indigo.

Additional Resources

Thvm greencaste raw denim:

Raw Denim Term - Caste

Source: thvm.com