Start with what the current site fails to do. Visitors cannot tell the offer. The team cannot edit it. Enquiries land in the wrong place. Those are the reasons to redesign. A new colour is not.
Then agree the pages that matter, the one next step on each, and who will update them. Check the content you can reuse and the content that should be rewritten. Only then look at the interface.
Before launch, read the site as a stranger: the service, the proof you actually have, and the way to enquire should be obvious.