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 Kagamine Rin.
Description[]
The Outfit's attire consists of a long white coat with yellow inner-fabric, a black collar with a yellow stripe, end sleeves that match the collar, and a yellow bow on the back, a yellow ascot, a white shirt with only the front side tucked in, black shorts with yellow buttons, teal three-finger rings with a white flower on both hands, black legwarmers, and white shoes with yellow soles. Additionally, Rin wears white headphones with a rainbow on each of the side handles, yellow eighth notes (♪) on the earpads, and her iconic bow is attached to the top handle.
Game appearances[]
The Outfit first appears in Hatsune Miku and Future Stars: Project Mirai where it can be unlocked by clearing "reverse rainbow" on Normal difficulty and can be bought for 5000 Mirai Points. It returns in Hatsune Miku: Project Mirai 2 and Project Mirai 2 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.