Font color changes on embedded card visuals

We have a Dashboard with many different visuals, all of which have white font colors that are set in both the reports themselves and in the Dashboard theme. We are also embedding this dashboard into our site. When we view the Dashboard in the Power BI service the font color is white (correct), but in the embedded Dashboard it changes from white to gray when we navigate away and return to the Dashboard. It only seems to happen on card visuals, and only on the data labels, not on the titles.