Sometimes, due to great aggrievement caused by the dealings of Krsna, the body changes color. The gopis therefore addressed the Lord thusly: "My dear Krsna, due to separation from You, all of the denizens of Vrndavana have changed their color. And because of this change of color even the great sage Narada was thinking of Vrndavana as a white island in the ocean of milk."
When Krsna and Balarama were present in the arena of Kamsa, Kamsa's body changed color. Similarly, Indra's face changed color when he saw that Krsna was protecting all the denizens of Braja by lifting Govardhan Hill. If the color change takes place due to excessive jubilation, the hue turns red. Because such a change of color is so rare, Srila Rupa Gosvami does not further discuss this point.
Link to this page: https://prabhupadabooks.com/nod/28/changing_of_bodily_color