We are currently working through all the themes to add Custom Colors support, and Yoko is on the list but not updated yet. Here's our todo list so far if you're interested:
Changing the color scheme of WordPress.com themes are a snap once Custom Colors support has been added. Check out how it works here:
I would recommend waiting for the colors update in your case because you're going to love it. However, I can totally walk through updating all the colors with CSS manually now if you'd like too.
Here is a CSS example that will change out the base link colors in the Ever After to colors I picked out that seem to match up with your current header image:
color: darkgoldenrod !important;
To try it out, add the CSS to your Appearance → Custom Design → CSS editor and click the Preview button.