Dr.StrangeLove was pretty much Cocco’s backing band from the start of her career. Negishi Takamune has so far produced every album (not counting Singer Songer, since that was produced by Kishida Shigeru of Quruli.)
So it was a nice tribute to her producer and session musicians when she covered the band’s "Rainbow".
Negishi and Susumu Osada (Dr.StrangeLove’s guitarist) aren’t exactly the best interpreters of their songs, but under Cocco’s hands, the versatility and appeal of the pair’s songwriting comes through. In short, she brought out the best parts.
I thought about providing an A-B comparison with the original song, but essentially, what you hear in Cocco’s version is what you would get (generally speaking) on Twin Suns, the album from whence it came.