This one is from tom, who was also involved in the original video. This design is all clear skies and rainbows! 
— Website description[1]
reverse rainbow (逆さまレインボー Sakasama Reinbō?) is an Outfit for Megurine Luka.
Description[]
The Outfit's attire consists of a long white short-sleeved coat with pink inner-fabric, a black collar with a blue stripe, black end sleeves, and a pink bow on the back, a gold woodwind-esque ornament with a blue jewel piece attached to the coat, a long white shirt with gold stripes on slits on the sides, a brown skirt, yellow three-finger rings with a white flower on both hands, black stockings, and dark yellow boots with small blue droplets on each side and brown soles. Additionally, Luka wears white headphones with a rainbow on each of the side handles and pink eighth notes (♪) on the earpads.
Game appearances[]
The Outfit first appears in Hatsune Miku and Future Stars: Project Mirai where it can be unlocked by clearing "reverse rainbow" twice on Hard difficulty and can be bought for 5000 Mirai Points. It returns in Hatsune Miku: Project Mirai 2 and Project Mirai DX where it can be unlocked by clearing the aforementioned song on any difficulty and can be bought for 5000 Mirai Points in Project Mirai 2 and 3000 Mirai Points in Project Mirai DX.