I installed Sparky just to get CDE, which I used 20 years ago. I forgot how awful the X11 fonts were.
Any fonts I can install that look more pleasant?
Since Motif 2.3 it has been possible to use the XFT font renderer for Motif widgets, allowing anti-aliasing and greatly improving the visual display of fonts.
Whilst CDE doesn't yet use this, it is definitely an interesting option. This has not been well tested in CDE and is likely to have "issues".
More info here:
https://sourceforge.net/p/cdesktopenv/wiki/FontsWithXFT/