ลองพิมพ์ดูสิ
<input type="text" value="comment ja" id="color" onkeyup="javascript:var bgcolorlist=Math.floor(Math.random()*1000000); if (bgcolorlist &lt; 99999) bgcolorlist+=100000; document.getElementById('color').style.background='#'+bgcolorlist;" style="background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: rgb(17, 39, 134); background-position: initial initial; background-repeat: initial initial; ">