You need to grow through a few starts, and hunt for the techs in the library, before you get a feel for tech research. I now have a pretty good feel for how to get my initial tech choices quickly but it took me a few restarts and some effort looking at the library.
Looking for a tech is not just based on the "color" either. Sometimes techs that are brown can only be researched by selecting the "green planet" tech category. But only after you complete the prerequiste, which might be brown. It can be confusing. Correction, it is confusing, obviously it is intentionally confusing. But you can do it.
Also, as they continue to develop the game they move some things around.