🎛 Review & Refine Colour Token values

[emirgens]

Description

Joint design + development review of the colour token values, framed by the 23 Jun decision to consolidate on static / semantic colour (dynamic dropped). The palette values are largely fine — the real work is evolving the static colours: expanding the scale. This is a continuation of the static colours, just expanded.

Why ship alongside (not edit in place)

The current scale (~15 steps) isn't enough. We cannot expand it in place: inserting a step shifts every colour's position in the palette generator and cascade-renames the scale (active → hover, hover → default, …), which would break every consumer.

Instead, the expanded static scale ships alongside the current colours (in its own library file) and the current set is left unmaintained / deactivated so consumers migrate at their own pace — the same deprecation pattern already used for components. (Reworked colour state names come from #4744.)

Scope

• Expand the static colour scale (current ~15 steps insufficient); reuse existing colour values where possible.
• Add alpha-channel colours to the static set (basis for the disabled-state approach — see 🎨 Implement Alpha‑Channel approach for disabled states #4741).
• Close known gaps:
  • Dataviz / infographic palette
  • More steps in the background-fill range (designers hit a missing hover/active step)
  • Hover / active guidance for non-button clickables (e.g. cards)
• Document that static and dynamic share the same dark-mode palette.
• Result imported to Tokens Studio.

Definition of Done

• Expanded static colour scale built in Figma (alongside the current set)
• Existing colour values reused where possible; gaps closed
• Alpha-channel colours added to the static set
• Expanded scale shipped alongside the current colours; current set marked unmaintained / deactivated
• Result imported to Tokens Studio
• Changelog prepared