Chāndogya Upaniṣad 6.4.3

6.4.3

yac candramaso rohitaṃ rūpaṃ tejasas tad rūpam \
yac chuklaṃ tad apām \
yat kṛṣṇaṃ tad annasya \
apāgāc candrāc candratvam \
vācārambhaṇaṃ vikāro nāmadheyaṃ trīṇi rūpāṇīty eva satyam \\604.3\

3. Whatever red form the moon has, is the form of heat; whatever white, the form of water; whatever dark, the form of food. The moonhood has gone from the moon: the modification is merely a verbal distinction, a name. The reality is just "the three forms."