White korma masala is the masala used for white korma, which is a mild, lighter colored korma. The flavor is milder and the spices vary slightly from regular korma which is a brown color.
For example, the white korma masala would include some of the following: ground cashews, coconut, cream, or ground almonds. The spices would be coriander, cumin, cardamon, ginger and cinnamon and probably not include garam masala, and possibly not garlic.