How to add colour to a Microsoft CRM Form Picklist

I recently got asked by a customer to change the colours of Service Cases based on their priority.  P1 = Red, P2 = Yellow, and P3 = Green. Whilst there is no standard capability within Microsoft CRM to perform this on Case Lists or Case Form, there is a form script which can be added to the Form OnLoad() to perform the change.

The colours are present within the picklist dropdown.

Upon selecting a value the picklist colour is then maintained on the form view.

The code required to make the above changes is as follows;

// Get the picklist 
var picklist = crmForm.all.contractservicelevelcode;
// Change colour to Red if P1 
var option = picklist.options[1]; = "#E55451";
// Change colour to Yellow if P2 
var option = picklist.options[2]; = "#FFF380";
// Change colour to Green if P3 
var option = picklist.options[3]; = "#5EFB6E";