A colour with a green, blue or purple bias — associated with calm, shade and freshness.
In Colourwise's classification, a colour whose OKLCH hue falls roughly between 130° and 320°.
Warm/cool is a design convention, not a measured physical property of light temperature.
Sage green and slate blue are cool colours.
Cool colours are commonly recommended for bright, south-facing rooms where extra warmth is less needed.