Spectrum Questions

• How does plasma make a campfire flame orange?
• Is human blood ever any color other than red?
• What is the color of the sun?
• Why are the microwaves in a microwave oven tuned to water?
• Why are there only six fundamental colors: red, orange, yellow, green, blue, and violet?
• Why does a rainbow contain a pure spread of spectral colors?
• Why was color invented by humans?