Sherlock's make-up secrets: Benedict Cumberbatch's green hair and Andrew Scott's guy-liner

She appeared with her husband Arwel Wyn Jones – who just happens to be Sherlock's production designer – at this week's Sherlock Holmes Convention in Vienna and revealed some precious secrets from the BBC1 drama. The Q&A is reported in full on somelikeitpink's tumblr but here are the highlights.

1. When Benedict Cumberbatch first did the pilot, his hair was dyed dark to resemble the famous Sherlock Holmes. What the make-up team didn't foresee were his bleached locks (he'd just played Van Gogh), which turned a lovely shade of green the day before filming began. Cue a last minute dash to the hairdressers....

2. Jim the IT guy had tinted eyelashes (according to Sherlock) but Jim Moriarty went one better. In addition to the slicked hair and pale pallor of Sherlock's arch-nemesis, the production team reached into their make-up bags to help Andrew Scott perfect Moriarty's "cold stare". What did they use? Guy-liner.

3. The moustache. A point of contention, apparently, when Martin Freeman had to sport the facial accessory for the start of series three. According to Pritchard-Jones, they had to try over ten different versions before Martin finally agreed to one. He also shaved it off sooner than originally planned in the script.

4. Rupert Graves flirts with Una Stubbs. (And she loves it!)

5. The licking scene between Charles Augustus Magnussen (played by Lars Mikkelsen) and Lady Smallwood (Lindsay Duncan) in His Last Vow resulted in a few queasy stomachs amongst the crew but the make-up team were on hand with tons of mouth wash, mints and some face wipes for poor Lindsay. Apparently a few of the takes were much worse than the one they ended up using.

6. Claire gets to hang out with Benedict Cumberbatch every morning. Sometimes he'll come in and have loads of lines to learn but then there are the days they turn the music up and have a party. A PARTY.