I am looking for a complete, updated database of new cars. It should
include the manufacturer, model, trim, and color. More information is
fine, but those four points are the minimum.

For Example:
Manufacturer: Acura
Models: MDX, RDX, RL, RSX, TL, TLX

Example Trim for new the Acura MDX: 4WD 4DR, 4WD 4DR Touring, etc.
Example Colors for the new Acura MDX: Amazon Green Metallic, Bullet
Silver Metallic, etc.

It should have the information for each car as shown above. 

I don't mind paying for this database, but I would like several
options to consider.

Thanks in advance!

The Swiss weekly journal "Revue Automobile" (in French) (= "Automobil
Revue" in German)
http://www.revueautomobile.ch/index.html
and
http://www.automobilrevue.ch/index.html
 
publishes a yearly catalogue "de toutes les voitures en production
actuellement dans le monde" (of all the cars currently being built
worldwide):
http://shop.automobilrevue.ch/shop/fr/produktdetail.asp?ProduktID=41684
and
http://shop.automobilrevue.ch/shop/de/produktdetail.asp?ProduktID=41684
 
Monthly updates are available online:
http://shop.automobilrevue.ch/shop/fr/produktdetail.asp?ProduktID=12498
and
http://shop.automobilrevue.ch/shop/de/produktdetail.asp?ProduktID=12498
 
Shop:
http://www.revueautomobile.ch/page_32.html
and
http://www.automobilrevue.ch/page_41.html

I suppose that details concerning colours are not included (but I'm not sure).

JATO Dynamics (www.jato.com) offers a number of databases that could
meet your needs. Their Car Specs database is used by manufacturers as
well as dealerships - they collate their information directly from the
manufactures and go into deep detail on each vehicle so it should meet
the requirements you specified.

See here for more info:
http://carspecs.jato.com/carspecs/Default.asp?Language=19&Country=us

You may be able to sign up for a 14 day trial at the Jato website.

Alternatively see here for internet sites using this data:
http://carspecs.jato.com/carspecs/SummaryDetail.asp?Language=7&Country=us&Menu=1&Summary=5