Here's the ANTLR HRC by Andrey Breslav.

ANTLR HRC is a Colorer highlighting profile for ANTLR v3 files.

Please, download here.

Installation instructions:

• place antlr.hrc file wherever you want
• modify your <colorer>/hrc/proto.hrc file as follows: add the following descriptor after <!-- rare languages --> comment

  <prototype name="antlr" group="rare" description="ANTLR">
    <location link="<path to antlr.hrc>"/>
    <filename>/\.(grammar|g|g3)$/i</filename>
    <firstline>/^(parser|lexer|tree|grammar)/</firstline>
  </prototype>