Forms :: Change Records Visual Attribute Depending On Certain Conditions

I have a database block that refreshes using a timer. In short, I list all open work pieces for a certain garage, displaying route, run, on_time, of_time, location grouped by garage, on_time, off_time

I need to highlight every garage with a different color. I am highlighting the on_time every time the garage changes.

The problem is, every time I move down the records, instead of keeping the previous garage color, and highlight the new garage on_time with a new color, the whole on_time column will be set to the current garage color.

I need to break down the block by color so the user can distinguish between the different garages, and the start and end time. Here is my code, I am putting it in when_new_record_instance of the work_block:

IF :work_bLock.current_garage = 9006 THEN
Set_Item_Property('work_block.on_time', BACKGROUND_COLOR, 'r191g223b191');
ELSIF :work_bLock.current_garage = 9002 THEN
Set_Item_Property('work_block.on_time', BACKGROUND_COLOR, 'r255g228b196');
ELSE
Set_Item_Property('work_block.on_time', BACKGROUND_COLOR, 'r255g250b250');
END IF;

I need the block to be 3 or more different colors depending on the garage.