Try "hud_scale 1"

The technical problem with bigger text is that the DOOM WADs don't supply individial letters of the bigger font, but instead use a patch for each string (map names, menu items...)

This makes it impossible to create arbitrary lines with this font in a way that would not infringe on DOOM's copyright (by ripping the letters pre-packaged) or work with different PWADs (by doing so in runtime).

This is definitely something we would like to address.

Odamex does in fact have its own "BIGFONT" as modern ZDoom calls it.  You might have noticed it in the intermission screen.  However, that's the only place where it's used....honestly I don't even know if the color can be changed.