Images were taken with just my iPhone on automatic.
Information from the UK Met Office website at:
https://www.metoffice.gov.uk/weather/learn-about/weather/optical-effects/rainbows/double-rainbows
How are double rainbows formed?
Double rainbows are formed when sunlight is reflected twice within a raindrop with the violet light that reaches the observer's eye coming from the higher raindrops and the red light from lower raindrops.
This means the sequence of colours is inverted compared to the primary rainbow, with the secondary bow appearing about 10 degrees above the primary bow.
Rainbows are refracted and reflected sunlight and are complicated:
http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/rbowpath.html
Rainbow Principles:
https://commons.wikimedia.org/wiki/File:Rainbow_principle.svg
https://old.atoptics.co.uk/rainbows/sec.htm
Now that was the science behind rainbows, but really, they are just a beautiful thing to see :-D