Hello! One of the first things that annoyed me when we finally got free exploration in Z-A was that I knew there was no way to complete some of these courses in the beginning. Or I started believing I have serious skill issues.
After a lot of hours, I discovered there are basically two types of courses, the normal ones and the Glide ones. The Glide ones can only be done once you unlock the Glide skill, so you can ignore those in the early game.
I've created a comprehensive list that shows the exact location of each Colorful Screw, and a little guidance on how to get them, if it isn't too straightforward. They all have checkmarks to keep track of them, with a checklist in the beginning. I also wrote where to find Racine Construction, if you're clueless like me and looked for it a lot longer than you should have.
In case you're wondering, the Screws are essential if you don't want to faint from two hits in Rogue Mega battles and would also like the EXP grind to be faster.
Edit: It's 100% now.
Here's the guide:
https://raiderking.com/pokemon-legends-z-a-all-colorful-screws-locations
by opreaadriann