Update Polaris colors and color tokens

[heyjoethomas]

Summary

An improved color token infrastructure will dramatically improve the experience of Shopifolk building for the Admin, increase mainline coverage of custom components by making Polaris more extensible, allow for large scale design changes with a lot more ease and speed in the future and allow us to improve the visual design of the Admin by hand picking a more cohesive and vibrant color palette that better meets merchant needs.## Issue summary

Outcomes

• Create new infrastructure for handling the new abstractions while only exposing what we want to ensure teams use the system properly
• Create new color palettes for both functional colors and accent/decoration colors
• Create new token naming conventions and semantic token
• Mapping tokens to Polaris components
• Get new tokens into repo

Tasks

• Create new color scales for primary palette
• Create new accent color palette
• Create naming convention for semantic tokens
• Map current tokens to new semantic tokens
• Test new colors on Polaris components and full screens across admin
• Add palette tokens to repo
• Add semantic tokens to repo

[alex-page]

3 more apps to go

• shop-server
• email
• pos-channel