Can anyone direct me to an AMA or other site detailing runway markings, i.e.color, line size, etc.? Thanks....Tom

I'm not sure there are any AMA standards regarding runway markings outside of competition rules.

Here's a link to the AMA online documents...

http://www.modelaircraft.org/documents.aspx

Our runway has a white center line, yellow "X"'s at both ends and a midpoint line (also white).

We have markers in the flight area that define the "box" for the pattern flyers as well as a "pilot box" for them to practice from.

http://www.modelaircraft.org/PDF-files/706.pdf
Nothing specific on how to mark your runway from the AMA other than a "center line".
On any runway the centerline will be white. Most clubs will use a 4" wide paint roller, a line stencil w/ spraycan or an aerosol line marker.
Some just use a centerline if at all and some go all out with solid lines on the outside edges of the runway and taxiways.
Another suggestion, go on the AMA website and surf through the clubs. You will be blown away at some of the flying sites these clubs have.

I wouldn't recommend white as that is the color of full scale aircraft runway markings....instead use yellow the color of fullscale taxi ways

These descriptions might be better found at the FAA. However, I don't know that the markings need to be any specific color. Only that paved strips should have a large X at the threshold of each runway end. I don't know that a centerline is required, it's just fun to land on and roll out on.

Somehow what was said above was repeated here. Deleted.

Thanks to all of you who responded. AMA has no recommendtions for markings and apparently it is up to each club's discretion.Thanks again for your input.