Manhattan – SoHo
89 Crosby St between Prince and Spring Sts
Even if you have to don a boring monotone suit for work every day, you can still add some undercover color thanks to Swedish great Björn Borg's line of rainbow underthings ($18 to $44). The tennis-themed concept shop (its first stateside boutique) offers candy-color printed underwear and tanks alongside miniature tennis tables available for customer use. Buy two and get one free when you mention TONY through June 19.
Find more shops at Time Out New York.