Does the 2017 Holden Colorado range have different automatic gearboxes

No, there was only one automatic gearbox, a six-speed unit that was vastly more popular than the other choice, a six-speed manual. For the 2017 model year, Holden upgraded the automatic transmission with what’s called a centrifugal pendulum absorber torque converter.

This absorber was a type of dampener designed to reduce vibrations form within the torque converter and improve the driveline’s smoothness. But this was applied to all 2017 Colorado diesels, meaning the transmission differs from a 2016 or earlier unit.