If you want to use the Listings package, you’ll need to include the following in your document preamble:
\usepackage{listings}
\usepackage[usenames,dvipsnames]{xcolor}
%%
%% Julia definition (c) 2014 Jubobs
%%
\lstdefinelanguage{Julia}%
{morekeywords={abstract,break,case,catch,const,continue,do,else,elseif,%
end,export,false,for,function,immutable,import,importall,if,in,%
macro,module,otherwise,quote,return,switch,true,try,type,typealias,%
using,while},%
sensitive=true,%
alsoother={$},%
morecomment=[l]\#,%
morecomment=[n]{\#=}{=\#},%
morestring=[s]{"}{"},%
morestring=[m]{'}{'},%
}[keywords,comments,strings]%
\lstset{%
language = Julia,
basicstyle = \ttfamily\footnotesize,
keywordstyle = \bfseries\color{blue},
stringstyle = \color{magenta},
commentstyle = \color{ForestGreen},
showstringspaces = false,
}