child theme font color customizations

Hello, I am new to WordPress and I am trying to do some customization with a child theme. I am using WPFolio, and I already activated the included child theme. I would like to customize the “highlight font” color so that the site title is a different color from the post and category titles (i.e. I want my site title to be yellow, and the smaller post titles to be a darker, more legible color).

Is there an easy way to do this? I searched for an answer on the WPFolio site and Google, can’t seem to find anything.

Thanks for your help!