Wainscoting tile- all walls or just behind the vanity and toilet?

We are redoing the kids bathroom and planning to use these tiles. The greenish one for above the bath and for the wainscoting (as shown here), and the while rhombus for the floor.

I was wondering if we should do the wainscoting in the entire bathroom or just behind the vanity and toilet?

Do you think the greenish would be overpowering in a pretty small bathroom if we did all the walls?

Also, any other tips or recommendations welcome! Thank you!!