Why do my stills come in over exposed

Hello all, really new to this system and still finding my feet.

I have been trying to use the stills button for a handful of grabs, however, even with the histogram on the camera showing as perfect, the stills come in all over exposed, what am i missing?

here is a shot to show what the pics look like straight from the camera.

( excuse the off white balance )

Try curves or colore wheels and bring them down. Are these DNG or another RAW?