if you aren't very critical on exact matches, what you CAN DO:
go to autozone, pep boys, etc. in the paint section they offer a whole bunch of different types of touch up paint. they make specifics that match honda paint specs. not exactly, but damn near close enough. just look for import paint and there should be names on the paint that tell you what brand name car the paint is for.
what you need entirely: primer (you will or should know what kind you need... the automotive kind!) the paint, sandpaper or brillo/scotch brite pads, and clear coat. there are two methods of sanding.
there is scotch brite soap sanding (wet sanding) and dry sandpaper sanding. while sandpaper results in a quicker removal of clear coat (which is what you NEED to remove before you re-paint) you shouldnt remove the paint, it's not necessary. just take all of the gloss off, anything that shines, dull it out to heck. after you are done sanding, wash the bumper with dishwashing soap. this soap contains no wax or harmful residue leaving contaminants, it's ideal for this. be sure to let the bumper air dry, make sure all the soap scum is off.
the next thing you should do is get hold of some Bulldog Adhesion Promoter. IT works for all automotive surfaces to promote paint adhesion, thus..
spray on EVEN light coats of this, you won't need more than 2 layers. keep the spray can at a consistent distance from the bumper and move in straight lines, be sure to ease off on the sprayer when you reach ends otherwise you will get drips.
after this, go ahead and do the same thing with the primer. i reccomend 2 LIGHT, EVEN coats of this just like the bulldog. once the primer is dry, all you need to do is paint the bumper! 3-4 coats is the ideal.
it is important to remember to spray the bumper in light coats at proper distance (2feet approx.) dont get impatient and do heavy coats, you will pay the price!!
the LAST thing is clear coat. its also available along with all the other stuff mentioned at pep boys, autozone, etc. allow the final layer of paint to dry 1-2hrs before applying clear coat spray. 2/3 coats of this is ideal.
the last thing to remember after everything is dry, do NOT expose the bumper to moisture condensation. let it sit in a DRY moderate area.
thats pretty much all you need to know about re-painting pieces of the car. it sounds like alot but its actually pretty fun once you get past the sanding and the payoff is usually great! patience is the absolute key. the whole process should cost less than 40 dollars