Whats the difference between the red and blue?

I noticed some of the lessons are red, some are blue.
Is there a difference between the courses with differing colors?

Where do you see this? On which page?

I think that “guided” courses are red. I don’t know the difference between guided courses and not-guided ones.

When im in the library, on my PC; choosing a lesson to take.
most are blue, but there are a couple red ones.

I have beginner 1 selected, for español.
I see some red and some blue courses.

Guided, hmm. No idea how that would work since I think they would all be inherently guided…

I think it’s just the way they’re organized. It looks to me like courses (blue) are divided into individual lessons, whereas collections (red) are divided into courses (blue) which are then divided into individual lessons.