I believe that in the BDSM world, the colour code is a standard that should be taught from the very start.
The only code that everyone should know is at least RED. The point is to make sure we have a word or code to say: it’s over, game finished.
Last night I was at L’Espace, a local fetish event, and a girl called red twice while her Master continued to play. So I yelled “Hey, she said RED!” in case he did not hear it. For them, a red was like a yellow — slow down, but not stop.
We use different codes to indicate levels of pleasure, pain, or energy, but it is very important to understand the meaning behind each code.

If red is their code for go slower but don’t stop, I hope they don’t drive in montreal XD