  We make systematic measurements of Raman anti-Stokes/Stokes (aS/S) ratios
using two different laser excitations (514 and 633 nm) of rhodamine 6G (RH6G)
on dried Ag colloids over a wide range of temperatures (100 to 350 K). We show
that a temperature scan allows the separation of the contributions to the aS/S
ratios from {\it resonance effects} and {\it heating/pumping}, thus decoupling
the two main aspects of the problem. The temperature rise is found to be larger
when employing the 633 nm laser. In addition, we find evidence for mode
specific vibrational pumping at higher laser power densities. We analyze our
results in the framework of ongoing discussion on laser heating/pumping under
SERS conditions.
