Do you identify Development, Test and Production web servers by colors?

As per rule "Do you have separate development, testing, and production environment?", it's better to use different background colors to identify Development, Test and Production servers.

CRM

Figure: Staging uses blue background

Figure: Production uses red background

The way to change the default background color is to edit the CRM CSS files. These changes aren't supported and may be overwritten when CRM Rollups are applied.

CRM 2015 and CRM 2016

Using theme feature to change the environment color.

Figure: Changing CRM 2016 UI by using theme feature

CRM 2013

Edit {{ CRM WEBSITE ROOT }}\_controls\navbar\navbar.css:

.navigationControl {
  background-color: #006600;
  margin: 0;
  z-index: 999;
  float: left;
  width: 100%;
  position: relative;
}

Figure: Edit the background color to reflect the environment

Figure: CRM 2013 with a green navigation bar

CRM 2011

Edit {{ CRM WEBSITE ROOT }}\_static\css\1033\cui.css, locate and modify the section ms-cui-tabBody so that it reads:

background-color: #ffffff;

Change color to a suitable color for the environment:

background-color: #bbffaa;

Figure: CRM Ribbon color green to signify production environment

CRM 4

Edit, {{ CRM WEBSITE ROOT }}\_common\styles\global.css.aspx

body.stage
{
    <% if (CrmStyles.IsRightToLeft) { %>
        dir:rtl;
    <%} %>
    border-top:1px solid #6893cf;

    /* background-color: #d6e8ff; */

    background-color: #ffff00;

    padding: 4px;

    /* background-repeat: repeat-x;

    background-image: url(/_imgs/app_back.gif);
    */
}

Figure: In C:\Inetpub\wwwroot\\_common\styles\global.css.aspx comment out and change the reference in yellow so the users know what server they are on

Figure: Color of CRM Development Server - Red

Figure: Color of CRM Test Server - Yellow

Figure: Color of CRM Production Server - Default

SharePoint Online

In SharePoint Online, we use Theme colours to differentiate between Production and Development environments.

To change the Theme, simply navigate to Site Settings | Change The Look | Theme

Development - Default Microsoft Blue Theme

Production - SSW Custom Theme

Figure: Selecting Red SSW Custom theme for Production

More about SharePoint Online custom themes: https://learn.microsoft.com/en-us/sharepoint/dev/general-development/how-to-deploy-a-custom-theme-in-sharepoint