I figured it out!

I'm so proud of myself! I figured out how to change the font colour in my blog header. Whew.
For future reference, I'm going to type it out here:

1. Click on "Design" at the top of the page.
2. Click on "Template Designer".
3. Click on "Advanced" in left hand column.
4. Click on "Blog Title".
5. Click on "Blog Title Color"

Voila!