Hi ​@InADaysWork 

I don't believe there is a built-in functionality in PSO that allows the DSE or any other service to automatically change the colour of a Shift or the Shift_Type based on the type of the activities (activity_type_id)   scheduled within it.

However I guess this requirement can be fulfilled in the following way,

The Shift_Type entity can be used to visually categorize different kinds of shifts. It includes a colour attribute to control how the shift appears on the Scheduling Gantt.

1. Define a New Shift Type:
   First, you need to create a new Shift_Type to represent the "Delivery Work." (Assuming you have a default shift_type for “Tech work”. You would send this as part of your data load. or if you are using PSO ARP this can be achieved using the shift categories as well.

   Example XML

   <Shift_Type>
     <id>DELIVERY</id>
     <description>Delivery Truck Work</description>
     <colour>#FFC300</colour> 
   </Shift_Type>

2. Assign the Shift Type to the Delivery Shifts:
   When your external system knows that a technician is scheduled for delivery work on a particular day, it needs to update that day's Shift record in PSO and set the shift_type_id to "DELIVERY". (This assuming that a tech will be assigned with either only delivery work or tech work on given day based on your statement “when tech is driving a delivery truck in order to know that the tech is not doing tech work those days”)

   Example XML

   <Shift>
     <id>SomeUniqueShiftID</id>
     <resource_id>YourTechnicianID</resource_id>
     <start_datetime>2025-09-20T08:00:00</start_datetime>
     <end_datetime>2025-09-20T17:00:00</end_datetime>
     <shift_type_id>DELIVERY</shift_type_id>
   </Shift>

Once this data is loaded, the PSO Scheduling Gantt will automatically display the shifts for that technician with the color you defined:

• Normal "Tech Work" Shifts: Will appear in the default shift color.

• "Delivery Work" Shifts: Will appear in the new color (e.g., orange).

This provides an immediate and clear visual distinction for the dispatchers, allowing them to see at a glance when a technician is on a delivery shift versus a standard technical work shift, directly fulfilling the customer's requirement. However this may not be a feasible solution as it relies on the external application integrated to PSO. 

I have attached a sample load and a shift_type update xml files for your reference.

Thank you, Sachitra_W, for your workaround suggestions! What we’ve tested and seems to be a simple solution is to have FSM pass a calendar exception for that day’s shift when a resource is in a delivery truck vs. a tech truck. Seems to work. It would have been nice just to be able to filter on skills in PSO since trucks are skills, but this appears to do the trick. Again, thanks for the great suggestions.