I have been programming for a long time in BlueJ and get used to some of stupid, yet useful things it has, like boxing the code between brackets, like in the code seen here: 
Do you know of any IDE or plugin for it that can do this? BlueJ is too simple for my needs and it only allows to program in Java.
I started programming this year too, also with BlueJ. After a few months we switched to Netbeans and I had exactly the same question as you.
When I look at your screenshot now, I don’t like it at all anymore… I suggest you just start using Netbeans, make some programs and once you’re used to it, you won’t need those colours. In fact, I wouldn’t want them anymore now.
I know I’m not answering your question, but just leave BlueJ. 😉