Hanging up chains with blue beads
Firstly:
Hanging Qur’aan on the walls is not appropriate as it involves a number of things that are haraam. These have been explained in the answer to question no. 254.
Secondly:
There is nothing wrong with hanging up chains that include blue beads for the purpose of adornment, so long as there is no false belief involved such as the belief that they bring good luck or ward off the evil eye. See also question no. 10543.
Nevertheless it is better not to hang up these things, because most people hang them up in the belief that they ward off the evil eye or protect one from hasad (destructive envy), so hanging them up is an imitation of these people, and some people may think badly of him if they see these beads, and think that he has hung it up to ward off the evil eye, and some people may follow his example in that.
To sum up, there are a number of reservations about hanging them up, so it is better not to do that.
And Allaah knows best.