You could argue that most of the bills dispensed from the Green Machine ATMs are green $20CAN bills, but a great deal of red $50CAN bills are also dispensed.
Red and Green Machine?
On an unrelated tangent, the $20CAN and $50CAN bills are printed on plastic. They have clear stripe areas with hologram stuff going on in the stripes. Kinda fun. And I must say that I've grown fond of the $1CAN and $2CAN coins. They are very handy.