// Initialize button with users's prefered color let changeColor = document.getElementById("changeColor"); chrome.storage.sync.get("color", ({ color }) => { changeColor.style.backgroundColor = color; }); // When the button is clicked, inject setPageBackgroundColor into current page changeColor.addEventListener("click", async () => { let [tab] = await chrome.tabs.query({ active: true, currentWindow: true }); chrome.scripting.executeScript({ target: { tabId: tab.id }, function: setPageBackgroundColor, }); }); // The body of this function will be execuetd as a content script inside the // current page function setPageBackgroundColor() { chrome.storage.sync.get("color", ({ color }) => { document.body.style.backgroundColor = color; }); }