@jfrancis, thanks for your response. We do not know which colour is the default because it changes based on the OS and the custom theme used by the user. When this extension is enabled, it picks the colour as I mentioned. While resetting, I want this colour to be put back. So we can not send/set this data via the settings schema.
But I think your idea of settings schema is the only way to trigger something we can set in the extension.js file along with settings. I will try in this way and get back to you soon.