1.) As the sun light travels along path through as atmosphere to reach our eyes, the blue light has been mostly remove living mostly red and yellow light remain since red light waves are scattered the list by atmospheric gas molecules
2.) Rainbows are formed when it’s misty or spray the sky with water. It’s not solely just from after a rain; you only need water that can act at as prism and light to shine to create a rainbow.
3.) Having gold at the end of rainbow is just a myth since you can never reach the end of the rainbow. A rainbow is caused by dispersion of light in water droplet which is why they occur when sun comes out after rain.