Changing Blog Header

Hi — I’m so new to setting up a blog that I’m not even quite sure how to ask this.

I’m using WP theme – Blog New. I would like to change the background color, font color and the size of the font in the header of my blog. Is that even possible. I found where to change the font color, but it changes the font color for all headings. Is it possible to set up different colors for different headings?

Thanks for your help!
Paddi

The page I need help with: [log in to see the link]