During nut production and processing, colour changes can occur at multiple stages due to various factors. Drying after harvest, especially at high temperatures, can slightly darken the nuts. Roasting triggers caramelization of natural sugars and the Maillard reaction, producing colours from light golden to deep brown depending on time and temperature. Seasoning and processingāsuch as adding salt, spices, caramel, honey, or sugarācan darken the surface or add a glossy layer, while blanching removes skins and lightens the appearance. Over time, storage and oxidation caused by light, oxygen, or moisture exposure can lead to uneven darkening or gray spots, signalling quality deterioration. See more