深色 (shēn sè) literally combines 深 (shēn), meaning 'deep' or 'intense', and 色 (sè), meaning 'color'. Together, it refers to any color with low lightness—such as navy blue, charcoal gray, forest green, or burgundy—and is used both as a noun ('a dark color') and an adjective ('dark-colored'). It contrasts directly with 浅色 (qiǎn sè, 'light color').

This term appears frequently in everyday contexts like clothing descriptions, interior design, food presentation (e.g., dark-fleshed fish), and animal coat patterns—especially when distinguishing between light- and dark-coated breeds (e.g., deep-colored pandas or Siamese cats). Unlike the more technical term 暗色 (àn sè, 'dull/dim color'), 深色 emphasizes saturation and depth rather than lack of brightness, making it neutral and widely appropriate in both spoken and written Chinese.