Tyria has a TON of forgiveness on carto. finish the rest of the campaign and you most likely won't need the red part. The greens are completely unnecessary.
The red is unlocked in The Great Northern Wall mission. You'll find that when you are running back at the end of the mission that there is actually quite a large area out to the side (which is the area you haven't explored).
Regarding the other bits, forget about them. They're negligible. For 100% in the title you don't need to explore literally everything. There's a fair bit of leeway.
What program did you use to edit the screenshot? I ask because I have some cartography stumpers in Cantha that have me ready to chew my way through my keyboard.
The area by the arena is not mappable, i had that same problem the other is accessed by the mission, if you need help pm me in game and i can show you how to do that. Tyria was my biggest headache for that. Don't worry about the areas you have circled in green. Just work on the the area that you have circled in red.