[R] grayscale wireframe??

[Marlin Keith Cox]

I need grayscale formatting for a wireframe.
The only col.regions that I can find are color palettes are all colored:

rainbow(n, s = 1, v = 1, start = 0, end = max(1,n - 1)/n,
    gamma = 1, alpha = 1)
heat.colors(n, alpha = 1)
terrain.colors(n, alpha = 1)
topo.colors(n, alpha = 1)
cm.colors(n, alpha = 1)

The code follows:

X11()
library(lattice)
par(family="serif", cex=1.2)
wireframe(z ~ y*x, mat.df,
          drape = TRUE,col.regions=rainbow(100),
          zlab = list("Water mass error (%)",rot=90), zlim=c(-50,180),
          xlab = list("Resistance error (%)",rot=-9),
          ylab = list("Length error (%)",rot=38),
          scales = list(arrows = FALSE),
	    screen = list(z = -35, x = -77, y = 10))


-- 
M. Keith Cox, Ph.D.
Alaska NOAA Fisheries, National Marine Fisheries Service
Auke Bay Laboratories
17109 Pt. Lena Loop Rd.
Juneau, AK 99801
Keith.Cox at noaa.gov
marlinkcox at gmail.com
U.S. (907) 789-6603