Jenna's recent extensive overhaul of the CMWGE miraculous-arc-to-color-correspondence system brought up this idea. It was implicit in the overhaul, but I figured it might be worth making it even more explicit:
The correspondences of Arc to color and type are malleable and can be houseruled.
For example, it has been long bantered about in the CMWGE fanbase that maybe The Ace should be the Immortal Gold arc instead of the Frantic Gold arc.
(Historical tangent: The reason why The Ace isn't Immortal Gold is from how it was developed. At an early stage of development for CMWGE, back when it was still attached by umbilical cord to Nobilis, Frantic was supposed to be where Noble-and-comparable abilities went, Immortal for Imperator-shaped things, and Sickly for Excrucian-shaped things. This organization was thrown out the window once it became clear that Arcs did not align nearly that neatly to archetypes, but that's why The Ace is Frantic Gold - all the arcs that were directly repurposed from the four Nobilis stats were intended to be Frantic.)
Anyway. The 24 color-to-arc correspondences given are not the only ones that can exist. You can move them around, if you'd like - I'll note a few things about that, though:
Level 0 abilities are often attached to the arc color rather than the arc powerset. As such, you may get better results by leaving them in place. For example, I think Self-Made (Sickly Red) is taking the Desmene ability from Of A Certain Place (former Sickly Purple) when it becomes Impresario (Sickly Purple).
The flavor text of an arc can be changed very radically without changing the underlying technical structure. The Persona arc - the one called Knave of Hearts, which may or may not have the wrong name due to Deceiver shenanigans - stole the flavor off what was supposed to be a completely different Sickly Red arc (also named Knave of Hearts, because presumably the title of it is also a flavor text that you get to steal).
So if you ever find yourself staring at a character and thinking "I swear this character is on Become Somebody, but that their pursued arc is Sickly Orange and not Frantic Orange", you can houserule this kind of thing.