Founder of online jewellery retailer MyFlashTrash, Amber was OBVIOUSLY at the shindig, wearing an all black All Saints ensemble.
Unsurprisingly, fellow Made In Chelsea-er Rosie attended the Marylebone launch and rolled up to the door in a decidedly smart outfit.
The 22-year-old mastered the monochrome trend in a cut-out crop top, white tailored jacket and slouchy suit trousers, teeing the whole look off with an enviable tote bag.
However, a much-needed slice of Essex came in the form of Lydia. The Essex-girl-cum-total-style-icon teamed a lacy peplum with casual jeans and a killer bulky clutch. Matching her shoes to her lippy Lydia, read the smart-cas dress code down to the letter.
AND as far as reality telly feuds go there didn't seem to be a whisper of one here. The TOWIE fave even tweeted her host Amber before arriving at the par-tay,
- Lydia Bright (@LydiaRoseBright) January 28, 2013
There may not have been any blood spilt between the rival telly stars, but which girl pipped the others to the fash post?
Whether you're in camp MIC or TOWIE we could all take style notes from Rosie's monochrome moment. Shop these Spring/Summer 2013 wardrobe stapels and stay ahead of the fash pack...