The learning curve never ends.
This evolution is compliments of my proofreader who just handed back my most recent novel "Slaves of Circumstance" and part of my "Man on the Run" series (Volume V). Until now, I was satisfied with a content edit. A content edit is AMAZING and should be enough. It is a line-by-line edit and feedback of your entire novel. Expensive but worth it. The proofreader is there to catch anything that isn't caught by the previous sieve. Hence, my transition to American spelling. To me, colour seems less so as color; utilise isn't as effective as utilize but that is the way things are. Tough beans, my friends!