$50 bill is blue

$20 bill is green

$10 bill is yellow

$5 bill is pink

$1 bill has no color

It's the same color scheme for today's Federal Reserve notes as for the old Monopoly board game. It's just a sly reminder from the bankers that the money becomes worthless when everyone stops playing the game.

Many years ago they removed the word pay from the face of the note. Now it says legal tender, which is something given in lieu of payment. That makes it more of an IOU be passed around, and it requires your faith in it to make it work.