There is no law against it. Although the CJ has branded me as one only responsible for tables and chairs, with due respect, I do know one or two things about the judiciary without having to sit on the bench. When it comes to matters pertaining to public interest, like the backlog of cases, impropriety of certain methods of doing things, we are free to comment. Contempt of court is when you pass an opinion on a case that is still ongoing or disparage the judges in a manner that they cannot defend themselves. You should not bring odium to their character.
Contempt is rather restrictive in that manner.
But other than that, you can comment on the affairs of the judiciary, with respect to public interest. It's difficult to pinpoint what a judge can and cannot do outside courtroom hours, but definitely to be circumspect about personal relations is one of them. If a judge is seen too much inclined toward certain persons, it could conjure up a difficult position. The principle against bias is one of the pillars of the rule of law. It is not difficult to envisage that the more free one is from such infringements, the better.