[R] Lattice z colours when using formula class

[Grace Garner]

Dear all,

I'm using Windows 7, R version 2.15.0 and lattice_0.20-6.

I'm plotting observed data in lattice using wireframe(). I have 3 
matrices of observed values (Temp,Dist,Time) and I'm using the formula 
method (Temp~Dist*Time).

How do I instruct wireframe to colour the plot surface based on the 
heights of my z data (Temp) only?

At present I do not understand how the colours in the colourkey relate 
to either my z, x or y data.

I include below my code:

mycols<-colorRampPalette(c("dodgerblue", "firebrick"), space="rgb")

wireframe(Temp~Dist*Time,
            shade=F, drape=T, colorkey = T, col.regions=mycols(200), 
col="transparent")

Thank you,
Grace