Hi, I can see 3 threads created for this question today, and it is not necessary to create multiple threads\questions for the same issue. if anything, multiple questions are less likely to result in a clear result\answer.
With regard to your question, the VIP flag is OOB ServiceNow field and there is OOB functionality that sets the form call_id field to red and shows the VIP icon on both form and list incident views.
View VIP status for a caller in incident (servicenow.com)
If you want to alter the Incident priority for a VIP caller then you can use a before insert\update Business rule triggered when caller_id field changes, this should set the Priority to P1
if(current.caller_id.vip == true) {
current.impact = 1;
current.urgency = 1;
}
You could also use field styles to set other field colors, if you need additional visual warning and there are plenty of OOB examples in a PDI.
/sys_ui_style_list.do?sysparm_query=&sysparm_first_row=1&sysparm_view=
Define field styles (servicenow.com)
