Support for site wide custom colour palette and customisable areas

[MitchAnderson93]

1. Colour patterns:

As per the specification in Figma (colour matrix/brand hierarchy):
https://www.figma.com/design/qKsxl3ogIlBp7dafgxXuCA/QLD-GOV-DDS?node-id=45445-46542&t=u8K2kc6GuFTlIPl1-0 and the use of alternative colours on:
https://www.queenslandsavers.qld.gov.au/ (and likely other websites in future)

The qds-bs5 project should:

• Have full support for generic colour tokens e.g. Primary button bg should appear as per the instances bespoke colour palette:

^ In this instance, body components still have the sapphire action colour (incorrect)

Use in campaign sites/non SWE (simple):

• Colours can be overridden after stylesheet loads (non franchise/non SWE):

<style>
   :root 
   [list of vars)
</style>

Use in campaign sites (advanced):

• Forking qgds-tokens and generating their own in Figma (re-usable token)

• Any additional repositories e.g. core/web components should also share the same colour referencing (so that a single root set of variables is interoperable across various combinations of use).

2. Areas of customisation:

As per the bespoke CTA box on ForGov (Preheader) and the Queensland Savers banner (fully custom design). The BS5 codebase should have known area's of customisation:

• CTA elements have a unique class/ID for projects to target with event listeners

• As per the login (3rd CTA option) area's like the custom banner should allow for customisations via a generic container (e.g. RAW HTML element is loaded into a content area)

Testing:

• To be tested in single kitchen sink example (SB)
• Tests can be used to verify colour compliance across all components
  (e.g. load this set of root vars, element X bg colour should be Y)

[MitchAnderson93]

Keen to hear your thoughts @re-becca @stvp-qld

As the intention is this will be re-used outside SWE (internal CMS/external CMS's) as per QLD savers example - custom colour pattern support and customisable areas vastly reduces debt required in each of these sites (debt has also been a blocker for this project, so it makes sense we reduce debt)