Geometry Preview in Different Display Modes

Hi All,

I'm running some DIVA analysis and attempting to create screenshot diagrams from the results.

I am finding that coloring a mesh using Custom Preview is giving me different value results in different Display Modes.

Currently only Ghosted gives me something that is bright enough to be legible. All other modes come out too dark. I've tried messing with each modes settings to see if I can't find the culprit setting, but I have had no luck. Is there a trick or workaround (short of baking each mesh analysis? I'd like to keep this script pretty limber).

Wireframe Mode:

Ghosted Mode:

Thanks