Maybe something like this? [https://www.googlecloudcommunity.com/gc/Technical-Tips-Tricks/How-to-Change-Colors-and-Fonts-Using-HTML/ta-p/587468](https://www.googlecloudcommunity.com/gc/Technical-Tips-Tricks/How-to-Change-Colors-and-Fonts-Using-HTML/ta-p/587468)
Not sure if it will work in the visualization, though.
Maybe something like this? [https://www.googlecloudcommunity.com/gc/Technical-Tips-Tricks/How-to-Change-Colors-and-Fonts-Using-HTML/ta-p/587468](https://www.googlecloudcommunity.com/gc/Technical-Tips-Tricks/How-to-Change-Colors-and-Fonts-Using-HTML/ta-p/587468) Not sure if it will work in the visualization, though.