There is no observed color coding for fuels in US.
Not for pumps, not for cans. I do have old (1970's ?) diesel can and it is blue.
People will always make mistakes and colors might help, but will not prevent.
I keep 3 different kinds of fuels -all in red cans and never made the mistake.
It is not that difficult to tell diesel from gas simply by smell, but they also pour quite differently.
Now to tell gasoline from 2-cycle mix takes rubbing between the fingers.
All working for 100 or more years - but only if you want it to.
