Hi Leslie!
The white box that appears around the text in your Call to Action block on the home page is one of the default styles added to that area when using the ‘Wedge’ content set for Crio. That box is meant to increase the readability of the text when overlayed on the background image for smaller devices, but since that text is now white on your website it is definitely having the opposite effect.
The best way to correct the design and remove that box is to use the Custom CSS feature available in the Crio theme Customizer. Here is a CSS snippet you can use to override the default style for that element and hide the white box:
.wedge-cta { background: none !important; }
Hopefully that snippet helps you achieve the design you are looking for smaller devices and please let us know if you have any other questions!