Set card background color to the value of a page variable

Hello, I am very new to AppGyver and have a quick question. I have successfully been able to use Get Record using an ID that I passed to a details page to get all of the data from my firebase database. I am wondering how I can take that page variable to then set the background of a card element to the hex color saved in my data base. When I try to use a formula to do so I see that there arn’t any page variables listed even though I am able to use them to set plain text on the page using the variables. How do I get the formula to successfully find the correct variable and color?