This post might already be dated, but last month McDonald's had a limited run sandwich for the cherry blossom season. The sauce was pink to go with the pink cherry blossoms. The teritama series combines teriyaki sauce (teri) and a cooked egg (tama) on a pork sandwich.
http://www.mcdonalds.co.jp/quality/basic_information/menu_info.php?mid=9065
Photo is a web capture for explanatory purposes, copyright belongs to the company.