I have two very small white sabae nems, when purchased they were clear and white and still are to be honest, they have purple dots in the tips. I've had them for three months and my tank was only running for a month before adding.... ( I can feel reefergladness spine shivering right now )
I still have them both, one of them has doubled in size, still cleary white colour which a suspect will change in time, but besides there colour they seem happy, my clarkii pair host them, i feed them once every two weeks, I used to feed them once every 3 days peeled prawn but I'm having a cyano issue ATM so I have reduced feeding for a while.
They swell and deflate, so I guess that is a good sign and they always grab the food straight away when feeding time.
If I could turn back the clock I would have waited longer before adding though, I definitely ran before walking.....but there still alive so I'm happy.