It is unlikely to be any proof of 'life' on Mars.
Perhaps the reason for the image being only black and white, is to prevent 'conspiracy theorists' from solving the filtering system NASA uses on their photographs?
[Source: Mail Online]: A white light captured emanating from Mars' surface is back and is as mysterious as ever. In a photo snapped by NASA's Curiosity rover, which has been traversing Mars' surface since 2012, the robotic explorer caught an anomaly mingled among the planet's rolling landscape. Floating just above a dune on the right side of the black-and-white image, Curiosity spotted a hard-to-miss white light. Images taken directly before and after the anomaly which are timestamped about a minute apart show up show no signs of any lights....read more>>>...
