Really stupid question about diesel

I have some yellow diesel cans that I'm pretty positive I put diesel fuel in but one of them has green color and the others are more clear. How can I confirm if I was stupid and put gas in my diesel containers?

Smell. Also put an ounce of each in small dishes and see which evaporates faster. The slowpoke will be the diesel.

A lot of ways to test.

Flash point is one. Take a teaspoon and put a lighter to it. If it lights immediately it's gas.

Viscosity, put a drop of known fuel next to a drop of your questionable fuel on a smooth metal surface. Tip the surface up at an angle and compare the speed they run at.

All the suggestions for fuel inspection are logical. I just want to mention that diesel fuel can be of different colors, for example, in Lithuania, diesel fuel intended for agriculture and industrial fishing is green.