What does "to be caught red-handed" mean?

To be caught in the act of doing something wrong or illegal

What does it mean if someone "shows their true colors"?

They reveal their real character or intentions.

 If someone "gets the green light," what does that mean?

They are given permission or approval to proceed.

They live in a place that has only green lights .

What is the meaning of the expression "to paint the town red"?

If someone "feels blue," how are they likely feeling?

What is the meaning of the expression "to see red"?