Make a custom property on the template for only the tag value, and then indirectly bind that to your target tag. Then, in another custom property, have your case statement inspect the value of the custom property that has the tag value. Pass the panel name and conveyor name into the template and use them for the indirect binding. Man its a friday.
In a second property's binding, use an expression that uses lookup
to look at a global dataset tag that has the colors/status numbers defined. Something along the lines of:
lookup(
{path.to.global.colors.tag},
{this.custom.conveyorStatus},
"black",
"Status",
"Color"
)
If you need to update colors, just adjust that global dataset.
Browsing the manual might help.