I Just received my opaque black acrylic templates from Applied Perspective. They came with brown tape to protect them, and the numbers on the templates have been etched in through the tape, leaving them pre-masked for painting in the numbers. What I am wondering is whether I can just color the numbers in with a metallic silver sharpie, or if I should use paint. I'm worried the sharpie will not show up well on the acrylic, but I also don't own any paint or brushes, and have no idea what type of paint I would need to use on acrylic. Spray paint is out of the question because the sides of the acrylic are not masked off, and I want to leave them bare. Thanks in advance for your help.
Applied Perspective Templates
I recall reading the official suggestion from one of those acrylic templates manufacturers, and they mentioned using crayon to fill in the lettering, as the surface where it's etched is rough enough to take the color, and it doesn't go overboard.
As for dismissing spray paint because the sides aren't masked, you can .. you know.. just mask the sides. All you need is some masking tape. 
Another idea is that you can buy a paint pen, which is probably what a metallic silver sharpie is anyway. (that's only a guess)
I could mask the sides, but that just adds a whole bunch more opportunity to screw it up. I thought about crayon too but wasn't sure it would get into all of the small edges. If that's what a manufacturer recommends, though, maybe I'll do that. Crayons seem pretty foolproof. 
I could mask the sides, but that just adds a whole bunch more opportunity to screw it up.
People use crayons to fill in the etched area on military rifles (safety selector, etc.), so tactical crayola in X-wing should be fine!
Seriously any basic acrylic paint from an art supply store, or wall-mart etc and a small brush. paint well into all the crevices, wait for it to dry for about 1-2 hours then remove the masking.
at this point take a toothpick and clean up any ares where the paint leaked under the masking as the paint while dry is still quite soft.
looks much better than any crayon.
You might be able to sharpen a crayon with a knife to make it a little more thin and accurate.
Quick update:
I checked specifically on Applied Perspectives website, and they are not the ones who suggested crayon, though I'm sure it works fine. Anyway, here is their official suggestion:
Most of our movement and range templates for X-Wing and Attack Wing are sold with a brown or white paper mask, which we engrave through to create the designs. If this is still present, color filling is as simple as painting over the mask into the engraved area and waiting for it to dry before peeling away the paper.
If there is no mask present, painting is still quite easy. Use your paint to fill in the engraved area. You do not need to be very careful about keeping it off the surface because after it dries, it is typically quite easy to scrape away the excess. When scraping away excess paint, make sure to use a material that is as soft or softer than the acrylic. Using a metal or hard plastic blade is very likely to scratch the acrylic. Instead, use the edge of another token, a guitar pick or some other plastic.
On mirrored acrylic, the masking is on the front, but the engraving is done through the back. To color fill mirrored templates, simply paint in the engraved area on the back. The mirroring will prevent any overpainting from showing through.
More news before I even finish posting this! (sort of a pre-edit) I just found Litko's crayon suggestion: Crayola makes the world go 'round.
I used White-out, and it looks great.