Apple Colour Palette contains two timelines. Orchard Leaf, Ground Green, and Ripening Gold follow the fruit toward harvest, when the peel's background colour begins moving from green toward greenish yellow.
Skin Blush is the variety-dependent overcolour that can sit above that ground colour. A red surface is visually persuasive, but colour is only one indicator of ripeness alongside flavour, size, sweetness, and texture.
Fresh Cut and Oxidised Flesh start the second timeline. USDA explains that slicing breaks apple cell walls and exposure to air produces brown pigment, so the last pair records handling rather than growth. Use the sequence when a design needs the whole fruit story, not one red icon.
