The datastores (if you haven't already figured this out) aren't necessary. They are only related to the feature I added of changing the dashboard color theme from within the running app.
I started by hard coding colors into my HRP for each element. But I was never happy with what I chose and kept tinkering. And it was annoying to change a color, then start the simulator and see if I liked it. To speed up the process, I changed the dashboard element colors to a variable. Then I could change the variable from within the app and find the color I liked in real time. Turned out I was still never completely happy, and had created multiple themes I liked (TNG, Borg, Voyager, Battle Bridge).
Here comes the datastore - Home Remote variables are reset to the defaults upon restarting the app. I needed a way to store the color variable so it would persist after a restart. As suggested by Bill/the Home Remote forums, I created multiple virtual devices on Hubitat to store a string for each color code I needed to save. I have so many because I created five themes and multiple colors in each. But now from within the Home Remote app I can save the color to Hubitat, and later restore it back to Home Remote.
All of that is completely unnecessary if you can decide on one color theme and stick to it.