When creating or editing Lightning apps, you can choose icons for
your utilities directly in the Lightning app wizard. Previously, you clicked a link to open a
new browser tab that listed the Salesforce Lightning Design System utility icons.
This change applies to Lightning Experience only.
By default, utilities without an assigned icon use the fallback icon.
To change the icon, remove the existing icon and click Choose Icon. A
window displays the available icons.
You can’t change the icon for some utilities, such as Notes and History.