[R] Polygon shading line colors

[Luke Spadavecchia]

Hi there,

I'm having trouble working out how to change the colors of polygon  
shading lines. If I plot a polygon with

polygon(poly,density=30,borders=gray(0.5))

I get gray borders but black shading lines; I have tried adding  
col=gray(0.5), bg=gray(0.5) and fg=gray(0.5), but no luck.
How can I change the colors of the shading? The help file doesn't  
seem to detail this, so any suggestions would be greatly appreciated.

Many thanks

Luke Spadavecchia