Car's front bumper

Do Mazda RX-8 year 2005 front bumpers come pre-painted?

You mean if you buy the bumper from the dealer???

Ask the dealer…Many cars do that these days…Some just come primed and you have to get it painted yourself.

If you mean bumper cover then no.
Even if they used to , the older a vehicle gets the less pre-colored items will be offered, interior trim as well.

Also check other parts supplires like Keystone and National Auto parts.