Change "read only" field color on case form

[sid23]

Hi,

We have "opened by" field as read only and we want to change the color of it to red. Now when its not read only i am able to change the color to red with the help of below client script but when its read only i am not able to. Any suggestions?

Script - 

function onLoad() {
var x = g_form.getReference('opened_by');

var openedByField = g_form.getElement('sys_display.' + g_form.getTableName() + '.opened_by');
if (x.vip == 'true')
openedByField.setStyle({color : "red"});
else
openedByField.setStyle({color : ""});
}

[Mrigank Gupta]

Try below script :

g_form.getControl(<field>).style.backgroundColor = color;

[sid23]

Hello Gupta,

Below is the script - 

function onLoad() {
var x = g_form.getReference('opened_by');

var openedByField = g_form.getElement('sys_display.' + g_form.getTableName() + '.opened_by');
if (x.vip == 'true')
openedByField.setStyle({color : "red"});
else
openedByField.setStyle({color : ""});
}

Can you guide me where to include the above script you have mentioned?