CiM's Rapunzel was formulated to be an opaque version of Crocus. While it is not an opaque version of crocus, being much lighter, it does go beautifully with Crocus.
Some people are reporting colour shift in different types of lighting, but I'm not seeing anything significant.
From the left, Rapunzel, Crocus, and Gelly's Sty on top. With maybe a blob of something else. Yes - the old, wonderful Gelly's Sty. Gorgeous, n'est pas?