* Add base color palette (#49356)

* add base color palette

* add some more comments

* fix formatting and color copy-pasta errors

* ignore existing bad base color usage

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Co-authored-by: Oisin Coveney <oisin@metabase.com>
# Conflicts:
#	.eslintrc.js
#	frontend/src/metabase/admin/settings/components/widgets/EmbeddingOption/use-embedding-settings-icon-colors.tsx
#	frontend/src/metabase/css/core/colors.module.css

* remove the thing that doesn't exist

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Co-authored-by: Ryan Laurie <30528226+iethree@users.noreply.github.com>
Co-authored-by: Ryan Laurie <iethree@gmail.com>