Take a look at photos of modern mining camps, polar bases and the like for inspiration.
As Rivera says, you often want to be VERY visible - I'd go for bright orange as well (we would pick the most difficult colour to paint, wouldn't we?) or blue or yellow depending on the terrain. That goes for buildings and clothing as well.
As well as whether the colony is new or old, consider its purpose and the money behind it. Is it a huge purpose-built showcase, a working camp, or just a bunch of cheap prefabricated buildings and modified shipping containers dumped from orbit? Are there repair facilities, or regular resupply drops? All these will affect the look and feel of the vehicles.