Imagine of using pink for a caution sign. How's gonna be? I learned from my psychology class back in the day in was in the Human-Computer Interaction program. People tend to be alert to warm color like yellow and they calm down when they see cool color like blue or green. What's up with that? Is that a nature thing or something that was accumulately influenced by us - human? Sometimes I think each one of us might not even see the same color. I mean, when I see the sky and I say it's blue, my brain might even interpret it differently from your brain. My blue can be your green, and your yellow could be my pink. This picture is just an example that I might see this caution ribbon and call it yellow. We cannot get inside each other's brain to proof that we interpret things that we perceive in the same way...