When an observer considers the colour of something, they might refer to:
Spectral colours and use names commonly associated with rainbows (ROYGBV).
A specific colour model such as RGB, CMYK or HSB.
A family of colours such as warm or cool colours.
Tints or shades of colours.
A palette of colours they have selected or are working with.
A broader vocabulary of colour names, such as dark red, vermilion, golden yellow, lemon yellow, pale yellow, greenish-yellow, chartreuse, leaf green, or light green.