The good ones are powder coated so you can get a colour of your choice to match the office.
Use a tool called a cable comb when you are running the cables to put the cables into very straight and neat bundles.
Here is the manufacturer of a good quality system for cable trays:
(they have many resellers. Your cabling contractor likely deals with a supplier who can get this)
Here is the cable comb tool for making straightened bundles of cables that look neat in they tray:
If you want something more enclosed then you can go to full conduit installation using metal pipes. The pipes can then be painted to match your ceiling colour.