I am a Canadian out of Western Canada, so things might be a bit different from where I am.
The BFI in my area bought from local vendors. It was not uncommon to see a WhiteGMC/ Volvo with a FEL Wittke, or Universal Handling body, although you would occasionally see C&O Ultralights(Dempster) and other manufacturers.
The FEL's had adjustable forks so that they could adjust for underbody or side forks. Most BFI bins had underbody forks.
Waste Management trucks were Maroon and White, until around 1998-1999 when they merged with Laidlaw Waste Systems. After that, everything turned green.