Colour is one of the first attributes children notice about anything. It’s something children pay attention to early on. The more colour names a child knows, the better equipped they will be in the nuances of description and visual expression. Artists tend to notice more about the world than most people because they look more carefully - they know that giving something your full attention means you can describe or represent it more accurately.
So a child who can say that their jacket is dark green or even olive green, is more likely to notice the jacket’s other features than a child who simply sees green. This ability to pay attention to the details supports all other areas of learning; it’s often true that the child who knows lots of colours is able to read more complex situations and understand - literally and metaphorically - that life is rarely black and white.
Colour tip: encourage use of similes, especially novel ones. My jacket is green like spinach, rather than dark green. This game is great on the move and helps foster creative thinking - as well as building a great vocabulary.