podnoms-web-extension/source/options.js

import optionsStorage from './options-storage';

optionsStorage.syncForm('#options-form');

const rangeInputs = [...document.querySelectorAll('input[type="range"][name^="color"]')];
const numberInputs = [...document.querySelectorAll('input[type="number"][name^="color"]')];
const output = document.querySelector('.color-output');

function updateColor() {
	output.style.backgroundColor = `rgb(${rangeInputs[0].value}, ${rangeInputs[1].value}, ${rangeInputs[2].value})`;
}

function updateInputField(event) {
	numberInputs[rangeInputs.indexOf(event.currentTarget)].value = event.currentTarget.value;
}

for (const input of rangeInputs) {
	input.addEventListener('input', updateColor);
	input.addEventListener('input', updateInputField);
}

window.addEventListener('load', updateColor);