[R] color.scale error

[Alaios]

Dear all
when I call color.scale like this:


require('plotrix')
colcolor<-color.scale(c(range_sr,sr),extremes=c("red","blue"))


Error in if (min(reds) < 0 || max(reds) > 1) reds <- rescale(reds, c(0,  : 
  missing value where TRUE/FALSE needed


range_sr 
[1] -10.00000000000000  44.02977813958366

str(sr)
 num [1:100, 1:100] 2.54 2.71 2.89 2.95 3.03 ...


this was working on simpler data sets before. 

How can I understand more what was the problem in depth.? I have read the source code of color.scale but unfortunately I did not make any progress to understand this error message. Is it possible to raise an exception before the error happens and see what went wrong?

Regards
Alex