Meaning: referring to the color from the Proto-Indian European root word rewd.
The color red has long been associated with danger and sin, and anger, aggression and war, likely because the planet Mars is red and associated with the Roman god of War, Mars.
Red has also been associated with courage and sacrifice, and even love. In many Asian countries, red is associated with fertility and success.
It could also be a nickname for someone with red hair, or has a ruddy complexion.