Welcome to PF, Rajeshmarndi.
There are a lot of night vision devices, including several generations each of IR and Starlight. They don't all operate the same way.
Starlights amplify ambient light, and I don't really know anything else about them.
IR units operate through infrared emission ('passive') or reflection ('active'), which means that the 'translation' is a B&W signal. That usually comes out as a particular colour gradient which depends upon the interpretation circuitry and visual display characteristics.