Orange color for research which is 1 tech away from availability

[Holy-Fire]

Currently, the tech tree screen uses green for already research tech, yellow for tech currently available for research, and red if you need to research more techs before you can research this one.

I think it will be very handy if there is another color designation (e.g. orange) for techs which are not currently available, but you need only 1 more tech before they are available.

In general, this makes it easier to see at a glance, when looking at the list of all techs in the panel in the left, which are candidates to be "next up".

But the main reason I think this can be useful is when you click on an available tech, and look at the tree structure to see what techs follow from it.

Often, I see a tech I want directly below it, and think "great, I'll research this one and then I can research that one". But upon closer inspection I see that this was false advertising, and there are actually more prerequisites (sometimes very advanced ones).

Of course, all information is available if you click on the future tech, but that can be tedious, especially if there are many techs which follow from a specific available tech. With my suggestion, when you look at the tree you can see at a glance exactly which techs are directly unlocked by the ones you're considering, and which will only be available later.

[PS. I'm back playing Factorio after a rather long hiatus, so it's a bit of an adjustment getting the hang of all changes to the tech tree, what I suggest could really help me get a handle on things]