[Schrödinger]

A simple salt metathesis reaction, I tried making the potassium salt of benzylamine (PhCH₂NH₂).

PhCH₂K + PhCH₂NH₂  PhCH₂NHK + toluene

I expected to see a white solid, PhCH₂NHK. Instead I get a pink solid. Is this its real colour? Or am I doing something wrong?

[discodermolide]

This may well be its actual colour.
Phenyl acetic acid is used to titrate n-Butyllithium, when the acid group has beed fully consumed the strong base starts to deprotonate the PhCH₂- group to give a yellow colour, the end point of the titration. Point is that many of such anions are coloured.

[Schrödinger]

I'm starting to believe it too. I did a lithium version of the reaction (in THF) and that turned out pink too. But then I pumped on it for a while to remove the solvent, and after 3 pentane washes, it now seems white. Perhaps it's a solvent thing... It might also be because of THF.