Mustard is warming, stimulating blood circulation and relaxing muscles.
Mustard seeds can have three colours: black, brown and white/yellow. Usually, mustard powder is made by grounding the white/yellow and brown variety together, and sometimes mix them with safran or turmeric to give an even more yellow colour and add taste.
Mustard seeds contain curcumin, a yellow pigment that is also present in turmeric and ginger roots. This compound is said to be antioxidant and anti-inflammatory.