It used to be available from Renault, but highly unlikely now, they couldn't supply any for my storm grey 200 Cup when I enquired a few years back.
Your local auto paint supply shop should be able to mix you up a batch, or there are a number of companies on the internet which provide touch up paint, I can't vouch for any of them in regards to the Trophy paint however, but as it's mixed to a code, I can't imagine they'd be far out.