Interactives hard coded copy colour cleanup

Having merged https://github.com/guardian/dotcom-rendering/pull/14049, which overrides hard coded body copy colours that have been set in interactives for years, this issue for the cleanup work required to revert this PR.

Old interactive atoms containing those hard coded values need to have them removed and then be redeployed. Once that's done we can revert the PR and close this issue.