His various girlfriends have tried to change his outfits: Penny had no success while Stephanie got him to wear dress shirts and sweaters (which he found uncomfortable), and Priya got him to briefly switch to dress shirts, waistcoats and dark slacks; he reverted to his original outfits after she left for India, but started eschewing his hoodies in favor of unbuttoned safari shirts and non-hooded jackets towards the end of the seventh season, a trend that continued into successive seasons.
Penny
Stephanie