https://www.pcgamer.com/fortnite-update-250-adds-impulse-grenades-lunar-new-year-themed-shrines-and-weapons/

Roses are red, violets are blue, impulse grenades are of rarity blue. 

By way of its latest update v2.5.0, Fortnite Battle Royale and its Save the World counterpart belatedly celebrate Valentine's with new impulse grenades and Lunar New Year-themed shrines, weapons and characters.