white background and NWS/NOAA logo

I have for some time run scripts that produce maps with white 
backgrounds. I have a copy of the coltbl.xmp file in my working 
directory with white as the first entry to achieve this. However, when I 
do this, when I use gptext to put on the NWS and NOAA logos, the white 
in the logos is switched to black.

Any ideas on how to resolve this? On the script I am working on right 
now, I run gpmap, gdplot2, and then gptext (to add the titles and logos).

In addition, the logos never look very clean. Would this be because of 
the size? I use size 2 and they look a little blurry. Any ideas on how 
to clean them up?

Example of what I am referring to at:
http://www.prh.noaa.gov/cphc/tc_graphics/EP072004_PROB34_F120_06.gif

Thanks!!

Maureen