[R] levelplot question

[Antje]

@Dieter:

 > You implicitly expect round().

 > Your question implies that you may also susceptible to the problem of
 > R FAQ 7.31, "Why doesn't R think these numbers are equal?"

No, I guess, you misunderstood my question. These vectors (at and col.regions) 
are given to levelplot together with some data which should be visualized.
I don't know how exactly levelplot works (I was asking for help to understand 
it) but somehow it creates something like bins from "at" and uses "col.regions" 
to display all datavalues within the same bin with the according color.
I'd like to know, which color to expect from levelplot for a certain datavalue 
(3.5)

Did I explain it somehow clear now?

Antje