How do I edit the text color in Appointments+

Here's my dilemma, I setup my appointments calendar at the base of my page. The problem is the color of some of the text is white, and the background is white. Is there a way to change these to just a plain black text?

I'm speaking mainly about the "our schedule" section and the "please check the appointment details below" Sections.

You can check it out on my main page