Why do some of the threads have green ticks against them?

[margomeoz]

And why do those threads have a post in green within them?

[kopenhagen5]

It simply means the OP has marked them as solved or answered.

[clair.de.lune]

Because invisible clair makes thread tick

[cherry*135 · Accepted solution]

Margo... if you choose kopenhagen's post as the solution to your question in the opening post, this thread would also  get a green tick.

It should say Accept as Solution when you are in this thread and you can choose which post you accept as solution, can choose more than one post too, I think. When you as opening poster select a post as the solution, that persons post then turns green.

If you don't want to choose a post as solution, that is OK too.

[just_me_karen]

Lol the green tick made Clair invisible 😄

[margomeoz]

Thanks am*3 I chose yours as the solution, so now I know.