A lot of English idioms use colors to describe feelings. Below are just a few examples.
Jessica was seeing red when her computer suddenly crashed.
When George brought home his expensive car, his neighbor Bill was green with envy.
After Susan’s boyfriend left her, she felt blue and cried all the time.
He was a yellow-bellied cowboy. He always ran away from a fight.(=coward)
John asked Nancy to marry him. He was tickled pink when she said yes.(=delighted)
