Start with the plant. Then check the form.

Toor (arhar) comes from pigeon pea; chana from chickpea; moong from green gram; urad from black gram; and masoor from lentil. These names describe different pulses, not different colours of the same ingredient. ICAR lists these five groups.

Check the packet for whole, split, and dehulled. Moong can appear green with its skin or yellow after splitting and removing the skin. Urad can appear black with its skin or pale after dehulling. Photographs below label the form shown; a whole-seed photograph is not a picture of split dal.

Regional names vary. The Hindi and Tamil names are a starting point, not an exhaustive dictionary. For two yellow dals that are often mixed up, read toor dal versus chana dal.