It is possible to repaint plastic trim, although, if it is textured, then the resultant surface will be also.
If you wish to attempt this, and have somewhere under cover to carry it out, then I would suggest giving the trim a good clean with some thinners the night before, then mask off thoroughly.
Apply a couple of coats of plastic primer (black) and allow to air dry - in essence, spray one trim, and work your way around the car, by the time you are back to your starting point, it'll be dry enough for another coat.
Since it's textured, I wouldn't bother rubbing it down.
Then, I would apply a couple of slightly heavier coats of this; http://www.ebay.co.uk/itm/Simoniz-To...item4d17f2d429
except on this occasion, I would use a heat gun or hairdrier on the final coat to ensure it dries without absorbing moisture and 'blooming'.
Then give it a few hours before removing the tape and taking the car outside, just to give the paint a chance to fully harden.