The Compendium of Caraka 5.7.10

5.7.10

svādīnāṃ pañca pañcānāṃ chāyā vividhalakṣaṇāḥ/
nābhasī nirmalā nilā sasnehā saprabheva ca //

There are five shadows of diverse characteristics belonging to the five elements:
the etheric is clear, blue, oily, and radiant;