The first thing that comes to mind is to put together a display using Task Widgets. It has Duration Format to change the appearance based on time. This is featured in the Tutorial for Kitchen Display using Tasks …
0-5: <color LightGreen><size 15>New Ticket</size></color>
5-10: <block 4 Yellow><color Black><size 15> Order is <m:> minutes old </size></color></block>
10-60:<block 4 red><bold><color white><size 15> ATTENTION: <m:> minutes passed!!! </size></color></bold></block>
60:<date:>
Another idea is to use {ENTITY STATE MINUTES:X}, assuming your Stations are Entities, or {TICKET STATE MINUTES:X} if they are not Entities. You could check how many minutes have passed on a a periodic basis (ie. use triggers to invoke a Rule to check the time), or use something like a Ticket Lister that changes the appearance of the Tickets when X minutes have passed.
You also have:
{CREATION MINUTES} Ticket Duration
{LAST ORDER MINUTES} Last Order Duration
{REPORT ENTITY STATE TOTAL DURATION:X} Entity State Total Duration
{REPORT ENTITY STATE TOTAL HOURS:X} Entity State Total Hours
{REPORT ENTITY STATE TOTAL MINUTES:X} Entity State Total Minutes
{REPORT ENTITY STATE TOTAL SECONDS:X} Entity State Total Seconds