brit, what we call 'colorum' back home are the privately-owned cars/vehicles that have no proper permits to operate as public transport vehicles. private taxis here in other words.

i prefer taking karwa buses over taxis anytime. you can actually save more if you have the smart card. they're safe, more or less reliable and they have a schedule. even if they're not always on time, at least you know exactly where they go and you do not get ripped off with the fare.