### Description When `theme="custom"` is specified without a `cta-accent-color` value, color values are null and this is the result: <img width="353" alt="Screen Shot 2021-06-23 at 10 27 03 AM" src="https://user-images.githubusercontent.com/3860311/123115358-0c8b0480-d40e-11eb-9e83-1d6918eb4a80.png"> We could give default values to the css variables and throw a warning. <img width="531" alt="Screen Shot 2021-06-23 at 10 29 18 AM" src="https://user-images.githubusercontent.com/3860311/123115528-2af10000-d40e-11eb-865c-2997aebdce15.png">