[cgs1019]

Neutrons are electrically neutral but they still interact electromagnetically (they're composed of charged quarks). They have a magnetic moment, for instance [1]. So they wouldn't be dark the way "dark matter" appears (heh) to be.

[1] - https://en.wikipedia.org/wiki/Neutron_magnetic_moment

[drjesusphd]

If dark matter particles had a magnetic moment, how would we know?

[gliese1337]

They would interact with photons, allowing us to see some effects of concentrations of dark matter against background light sources.