FluxCDE

Source (link to git-repo or to original if based on someone elses unmodified work): Add the source-code for this project on opencode.net

Description:

Imitates the look (but not feel) of the default theme for CDE/Motif from Solaris.

Not quite perfect, and can't be perfect because CDE and FluxBox are inherently different. Buttons for stick and shade were not included because CDE lacks them, and they would have to be designed to fit the imaginary CDE look if it did support them.
It also assumes that the close button is configured to be on the left, or else it looks funny.

In any case, it worked fine for me when I've been using it. Right now if you are a fan of CDE, you can install OpenCDE and get all the authentic look and feel.