Remove bespoke colours
Remove bespoke colours

These are all duplicates of things defined in the govuk_frontend_toolki
or things which are never used. The frontend_toolkit should be the
canonical source of colour so removing these.

robinwhittleton/static,alphagov/static,kalleth/static,alphagov/static,robinwhittleton/static,tadast/static,robinwhittleton/static,tadast/static,robinwhittleton/static,kalleth/static,kalleth/static,tadast/static,alphagov/static,tadast/static,kalleth/static