Tokyo Metro Rainbow Cakes

I saw this these at a subway kiosk this past week for the first time. After looking around on the internet I see it is at least the second set to go on sale. Japanese subway lines are color coded to help make sense of the seemingly random routes each line takes. These log-shaped cakes use three different lines and then adds a flavor which matches the color of the line. In this case all the choices are the following:
Hanzomon Line - purple - rum-raisin flavor 半蔵門線、ラムレーゾン
Yurakucho Line - yellow - Mont Blanc flavor 有楽町線、モンブラン
Chiyoda Line - green - azuki-matcha flavor 千代田線、あずき抹茶
The assortment is collectively called Tokyo Metro Rainbow. 東京メトロレインボウ

http://www.metocan.com/shop/item_detail?category_id=227402&item_id=904932

Photo is a web capture for explanatory purposes, copyright belongs to the company.