User blog comment:Western Gen/Speculations for Season 12/@comment-198.45.201.206-20140408222125/@comment-5746209-20140409172753

I think the "best option" about this topic is that we see them take off their helmets but not see their faces (or simply see their hair like Wash). This would give more human traits for the viewer, yet we still connect their helmet as their own identity and it leaves the fans to interpret for themselves what they actually look like. That's why their is so much fanart of RvB without their helmets, because we all imangine their faces differently base on their personality or hints we get in the series.

For example, I always thought of Simmons looking somewhat like me, because I have a similar personality, with parts of his face being cybernetic. However, Luke McKay thinks differently, having only "antennas" on the side of his head with messy hair and a long face (see Luke McKay's second drawing of him).

If we actually saw their faces, it wouldn't only risk going into the "uncanny valley" as Wes mentioned, but also destroy the perception of the character to many viewers. We all percieve differently and, as reality depends on ones perception of it, it would destroy the "reality" of others to a since.