[R] Plotting NLS profiles

[R Help]

Hello list,

I'm trying to plot nls profiles, but the plot.profile.nls function in
R doesn't seem to accept any plot.default variables.  Specifically,
I'd like to be able to change the x-axis title and the colors to black
and white.  Has anyone had any luck with this?

If not, is there a way to override to plotting colors, perhaps in par()?

Thanks,
Sam

fm1 <- nls(demand ~ SSasympOrig(Time, A, lrc), data = BOD)
pr1 <- profile(fm1, alpha = 0.05)
opar <- par(mfrow = c(2,2), oma = c(1.1, 0, 1.1, 0), las = 1)
plot(pr1, conf = c(95, 90, 80, 50)/100) # works fine
plot(pr1, conf = c(95, 90, 80, 50)/100,xlab=expression(theta),col=1) #
doesn't change