From Longman Dictionary of Contemporary Englishpalettepal‧ette /ˈpælət/ noun [countable] 1 
AVPa thin curved board that an artist uses to mix paints, holding it by putting his or her thumb through a hole at the edge2 [usually singular]AVP the colours that a particular artist uses or the colours in a particular painting3 the choice of colours or shapes that are available in a computer program
AVPa thin curved board that an artist uses to mix paints, holding it by putting his or her thumb through a hole at the edge2 [usually singular]AVP the colours that a particular artist uses or the colours in a particular painting3 the choice of colours or shapes that are available in a computer programExamples from the Corpus
palette• Object properties can include font, style type, fill or colour palette.• Finally, he decided to rest the notebook on his left hip, much as an artist holds his palette.• A very bright, transparent cool green, viridian has a place on many palettes.• Even Calvin Klein adds color, albeit pale, to his usually neutral palette.• The range of the artist's palette widened to include cobalt blue, ultramarine, chrome yellow and viridian green.• The surfaces are fresco-like, the pigment dry and chalky, and the palette severely restricted.• The paint on the palette was still moist because he had kept it under water in a pan in the kitchen.Origin palette (1700-1800) French Old French pale “spade” 