Agent Inbox - how to change SLA colors (traffic lights) in the Web UI

In agent inbox,

component: ICCMP_INBOX

view: InboxResultView and view: InboxItems

There is a field : overdue

This field displays red or green based on the due date of the inbox items.

I want to change this color based on my own custom logic.

Where do i write code for this ?

While debugging I see that the field Overdue has only the due date and time but on the web UI screen I see that this field has a red or green icon. Does anyone know where is the code written for displaying the sla color.

Thanks,

Karthik