Looking east out over the North Sea at Whitley Bay where I live on the afternoon of Monday 30th November 2020 I saw the following:
It was fascinating to see how bright it is within the primary rainbow and how this illuminates the sea at its end.
The primary rainbow forms from refraction and a single reflection inside the raindrops.In large drops (>1mm) red, green and violet are brightest but this is not the case here so I think we are looking at half millimetre or greater sized drops.
The secondary rainbow involves two reflections in the raindrops and is separated by about 10 degrees from the first, about five times the angular separation between red and violet in the primary rainbow.
