chrome-extensions-samples/functional-samples/sample.page-redder/service-worker.js

function reddenPage() {
  document.body.style.backgroundColor = 'red';
}

chrome.action.onClicked.addListener((tab) => {
  if (!tab.url.includes('chrome://')) {
    chrome.scripting.executeScript({
      target: { tabId: tab.id },
      function: reddenPage
    });
  }
});