If your camera produces pink images, this has to do with the mechanical IR filter (infrared filter). This is pushed in front of the lens when taking night photos. So a slight "clack" sound can also be heard during the first night photo of the day. When the camera switches back to day mode, the filter folds away again.
If the filter does not fold away, it is stuck or the light sensor has malfunctioned. Pink images are usually only a temporary phenomenon because the precision mechanics sometimes suffer due to the temperature fluctuations.