Khajjanīyasutta

sn22.79:4.1 And why do you call it perception?

sn22.79:4.2 It perceives; that’s why it’s called ‘perception’.

sn22.79:4.3 And what does it perceive?

sn22.79:4.4 It perceives blue, yellow, red, and white.

sn22.79:4.5 It perceives; that’s why it’s called ‘perception’.