Introduce a darker shade in the color scales for dark mode

[psirenny]

TailwindCSS recently added an additional 950 shade that works really well for dark mode. It allows for a gorgeous dark background without falling back to black. The TailwindUI Commit Template shows it off nicely:

To maintain parity, the light color scales could also add an additional lighter background shade. Indeed, many applications using Radix Colors already map the app background color to white, suggesting a desire for such a step.

[lumosminima]

Just ran into this I use color-shade-2 for body and bg-white for container and this gives a nice and calm light mode but doing the same in dark mode, bg-black ends up being too tonally different to the 12th shade. I follow darkest-to-light for UI layers in dark mode so if I use 12th shade as the blackest then the third UI layer (component cards) ends up being too bright. There really needs to be a more blacker shade for a more harmonious dark mode or at least give the formula (if there is one) for calculating more shades by ourselves.