@Hieronymus That is not too surprising, the antlr pre-processor converts your code to java as follows:-
int [] colors = {0xff000000, 0xffFFFFFF, 0xffa49e9c, 0xff0792fb, 0xff1a8236, 0xff2894c5, 0xff238570, 0xffa45b5a, 0xff485189};
I expect this of no help to @Eyetoof who wants to use ArrayList methods. The IntList is an apparently not well known convenience class that has a similar interface to the ArrayList.