This is additive color. Red, green and blue are the primary colors of white light. All three colors will result in white, the absence of all three will produce black. When two primary colors of light are added together, you get a color that is brighter than either of its components.
MYTH: A blood spot inside the egg means the egg is fertile. FACT: A blood spot inside an egg can occur at various points in a hen's reproductive system as a result of a blood vessel rupturing. It can be the result of a genetic predisposition, a vitamin A deficiency, or a random event.
However, your total fertile period is how long the egg is fertile and how long sperm can wait for the egg combined. This is known as your fertile window. While you are possibly fertile for seven days out of your cycle, the odds of conceiving at the far ends of that time period are small.