How should this title be written? Flour Power A Guide to the Modern Green Kitchen Flour Power, A Guide to the Modern Green Kitchen Flour Power: a guide to the modern green kitchen Flour Power; A Guide to the Modern Green Kitchen Flour Power: A Guide to the Modern Green Kitchen

Semicolon is used when separating 2 closely related independent clauses.

Colon is used when listing things, writing biblical references, between hours and minutes, proportion between 2 numbers, or between 2 clauses related to the first

So we'll write this one as-

Flour Power: A Guide to the Modern Green Kitchen

You're answer's the last choice