No, gas is only green if it used to as a stepping stone for wind or solar.

There is nothing prohibiting investing in nuclear energy, but you shouldn't be able to label that investment as green.

You can argue all day if nuclear is green or not, but most people on the street will not think of nuclear if I ask them what a green, safe and sustainable energy source is. At least in Germany, which of course represents the interest of their people.

So if you include nuclear in that label, for most people it will become meaningless and will fail to draw more investment.