Mitsubishi MOTORS Colt 2007 Owner's Manual page 36

Locking and unlocking
To lock without using the key
Front passenger's door
1
1-8
Rear door (5-door models)
Set the inside lock knob (1) to the locked position, and close
the door (2).
NOTE
● The driver's door cannot be locked using the inside lock
knob while the driver's door is open.