Like Viṣṇu, Kṛṣṇa is always shown colored blue. This might indicate a historical background as a darker-skinned non Aryan before being adopted into Vedic-Hindu religion.
The name “Kṛṣṇa” means “dark.”
While Kṛṣṇa is known as a trusted advisor in the Mahābhārata, is also popularly known as a lover and seducer, and a trickster of sorts.
As a warrior and king, he was also a kṣatriya (like Rāma), not a Brahmin, so he represented a less pure caste identity.