To help you to avoid wrong colour here are part numbers for a factory fitted
black switch
from a panel van:
Switch 7E5959551 (black)
Frame 7E0858099 (black)
View attachment 21556
The OEM switch has 180 ohm resistor built in between pins 1 and 4 (switch doesn't short circuit but 180 ohms) but anything less than 370 ohms seemed to work.
In my panel van the switch was active (to open the tailgate) only when doors were unlocked as it seemed to be just parallel to outside switch. Couldn't open it if doors were locked by remote. I didn't verify it it was different if locked from drivers door
.