Revamp Google Sheet Formatting

I need my existing Google Sheet tidied up so that everything looks consistent and is easier to read. There are a handful of individual sheets inside the file—no more than five in total—and each one should share the same visual language.

Here’s what I want done:

• Apply a clear, professional colour palette to headings and data cells.
• Standardise text alignment, font family, and font size across every tab.
• Build conditional-formatting rules so key figures highlight themselves automatically.

Nothing in the underlying data or any formulas should be disturbed; this is purely a visual refresh. Once you finish, I’d like a quick walkthrough (screenshare or brief set of notes) so I understand how to tweak the rules later if needed.