When I was 12, starting on my first episode of severe depression and going through a spiritual crisis, I went out, knelt in the rain in the yard, and asked if there was any deity out there to please send me a rainbow as a sign of his/her/its'/their existence.
Mind you, the sky was a solid gray overcast, like a bowl of steel.
I closed my eyes and prayed with sincerity and concentration, and when I opened them there was a small rainbow directly where I first opened my eyes towards.
I've mentioned this before.