"What lipstick was she wearing that one time?" We can't tell you how often we've wondered that question, so we rounded up five of our favourite recent looks and tracked down exactly which brand and shade each celebrity wore on their lips. If there's one lesson to be gleaned from our research, it's that it's time to try Obsessive Compulsive Cosmetics Lip Tar ($15). The name might be scary, but the pigment-packed tube of vegan colour delivers the ultimate punch of colour.Ashley Madekwe wears MAC Lipstick ($15) in Ruby Woo.

Brittany Snow wears Smashbox Photo Finish Lipstick in Glamorous, which, unfortunately, has been discontinued. But Smashbox Legendary Lipstick ($19) in Fig is almost identical!

Allison Williams wears Laura Mercier Lipliner ($20) in Natural and Laura Mercier Lipstain ($20) in Peach Glaze.

Karolina Kurkova wears Obsessive Compulsive Cosmetics Lip Tar ($16) in Vintage.

Emily Blunt wears Obsessive Compulsive Cosmetics Lip Tar ($16) in Demure with MAC Lip Glass ($15) layered on top.