Originally posted by WMCoolmon
In the latest mediaVPs, the dummy.pcx file is in either mv_core or mv_models. You can either extract and edit it, or create a 16x16 256-color dummy.pcx of your own in the data/maps folder. 
Once you've got one of those, just fill the image to the color you want.
If that doesn't work, and it's a source thing, it shouldn't be too hard to change.
Could you ever code in a feature where we can specify our own dummy.pcx file for each node, like a texture replacement feature? I have this plan of coloring nodes in Starforce according to who controls the system on the other side:
Green = Savaran Imperial Alliance
Blue = Earth Federation
Yellow = Vasudan Parliamentary Empire
Red = Microsol Consortium
White = Republic of Erigone
Cyan = Border Systems Coalition
Orange = Neo-Hammer of Light
Purple = Zica
Gray = Contested/pirate/independent
*sees new sexps*
Never mind...