What color is on the edge of the rainbow?
Q: What color is on the edge of the rainbow?
A: Red.
Q: What are the three primary colors?
A: The three primary colors are red, blue, and yellow.
Q: What is the wavelength range of red light?
A: The wavelength range of red light is between 630 and 740 nanometers.
Q: When is red used to mark something?
A: Red is sometimes used to mark things that are wrong, important or dangerous.
Q: What does a red warning sign usually signify?
A: A red warning sign usually signifies a need to stop.
