Change link color through Visual Tab

My client needs to be able to change individual link colors through the Visual Tab. I know you can change text colors that way, but when you apply them to links, they are overridden by the style sheet. My client does not want to have to use the text tab or any HTML or CSS to do this. I know that it is a trivial matter to do with HTML/CSS, but is there anyway to do it without having to code?

The theme is Twenty Twelve.

Thanks.