Whilst the likes of Snoop Dog and David Hasselhoff have shown their support for Warren Gatland's men by tweeting pictures of themselves wearing a Wales shirt, the WRU are urging the country to show the world that red is the season's most fashionable colour.
"This is probably going to feel like an extremely long week for most people in Wales as they wait for Saturday's big match," said WRU Group sales and marketing manager Craig Maxwell.
"There are a lot of nerves and much excitement in anticipation of the match against the French. Businesses allowing their staff to 'wear your jersey to work' will help build on that excitement on the eve of the biggest match in Wales' history, as shown here by Admiral staff in Cardiff.
"We are asking companies to allow staff to wear red jerseys to the office and then send in pictures to us to earn a chance of winning a signed Welsh jersey and tickets to the Wales v Australia match on 3 December at the Millennium Stadium.
In the wake of Saturday's win, the WRU have experienced an unprecedented demand for merchandise in the WRU store and online.
"Jerseys, especially, are flying off the shelves and we'd encourage people to get down to the WRU store at 8, Westgate Street as soon as possible whilst stocks last," added Maxwell.
"We're also offering fans a 15% discount on any Under Armour jersey bought in our store if they bring along their old official Reebok or Under Armour jerseys. The old jersey's will be donated to Rugby's Kit Aid."
Companies are also invited to send pictures of their staff in red jerseys to the WRU Facebook page and to email the best ones to firstname.lastname@example.org . Media Wales will then print the best pictures in the Western Mail. The Top 10 best snaps will win an official signed jersey and 10 tickets to see Wales v Australia.
Sensing a lift in the country's spirits after Saturday's performance, Maxwell said: "Rugby fever has well and truly hit the country and there's a real spirited atmosphere. Wales haven't been in a World Cup semi-final since 1987 and around 10 of the team weren't even born at that time, including our captain Sam Warburton.
"This is a young Welsh side with you a truely professional attitude. They are playing some really exciting rugby at the moment and everyone wants to be Welsh right now - so let's show how proud we really are in Wales and wear our red jerseys."