Looking back, I see that I've blogged quite a few times in different contexts about color.
For example, most of the security metrics I discuss are colored, and color is one of several important factors when communicating metrics, drawing the viewer's eye towards certain aspects for emphasis.
Traffic light RAG coloring (Red-Amber-Green) is more or less universally understood to represent a logical sequence of speed, intensity, threat level, concern or whatever - perhaps an over-used metaphor but effective nonetheless. Bright primary colors are commonly used on warning signs and indications, sometimes glinting or flashing for extra eye-catchiness.
Jeff Cooper, father of the "modern technique" of handgun shooting, raised the concept of Condition White, the state of mind of someone who is totally oblivious to a serious threat to their personal safety. Cooper's Color Code is readily adapted to the information risk and security context, for example in relation to a worker's state of alertness and readiness for an impending hack, malware infection or social engineering attack. We're currently exploring and expanding on that idea as part of December's awareness briefing for professionals on social engineering.