Hello Rui,
did a test on your Sandbox to be sure. I know what’s the issue: When i enter a color number (for example f6f6f6) and directly click save on the row element and save the page, the color number is filled in, but for some reason not registered. I need to open de row element setting again.
When i enter a color number and click somewhere else in the modal after enter the number and save the color is registered.
I want to work to fast.