This. As an ex-freelancer myself I totally understand you are talking about and is one of the main reasons why we came up with the idea of Finch. Apart from the collaboration (which comes in really handy when you work together with a nitpicky freelance designer), you can think about Finch as a browser developer tool with an UI that can save the changes you make.

Page colors, fonts and text styles already are on our roadmap marked as "must-have" ;)