Given that Chromis are here, Zeron can't be far behind.

The Zeron are a simbiotic species of shape-shifters, in their natural form they are monochromatic, featureless humanoids (they can be blue, green, red or white), but they can assume the form of any other humanoid species, to better blend in.

...and they might be everywhere...

The girl in the middle is a just 'shifted red Zeron.