How can I change the color of the labels in the Appointment Slots widget?

The question text in the top box (class times) is black so it blends in with the background of the transparent image. How do we change the question text for each of these questions to white so we can see it over the background? In these add-on modules, there's no clear way of how to change the text color. I've circled the example in red on the screenshot.

I cloned your form and checked the Appointment Slots widget you added. I noticed you have the following CSS Codes added:

.form-line-active {

   background:#000;

   color:#fff;

}

To set the color of the labels to white, remove all those codes above and replace them with the following:

.checklist label {

   color: #ffffff;

}

RESULT: