Add hmrc colour variable
Add hmrc colour variable

https://www.pivotaltracker.com/story/show/53235311

alphagov/govuk_frontend_toolkit,alphagov/govuk_frontend_toolkit,TFOH/govuk_frontend_toolkit,TFOH/govuk_frontend_toolkit,ministryofjustice/govuk_frontend_toolkit,TFOH/govuk_frontend_toolkit,quis/govuk_frontend_toolkit,quis/govuk_frontend_toolkit,TFOH/govuk_frontend_toolkit,quis/govuk_frontend_toolkit,alphagov/govuk_frontend_toolkit,quis/govuk_frontend_toolkit,alphagov/govuk_frontend_toolkit,ministryofjustice/govuk_frontend_toolkit