why did my image turn grey??

Thank you for the screen shots, @hendy_5450 —this is a display performance setting. Somehow, your settings were changed to Fast Display. 

The controls are in three places:

1. Object > Display Performance > High Quality/Typical controls the view single selected image
2. View > Display Performance > High Quality/Typical controls the view of all images in the document
3. Preferences > Display Performance > High Quality/Typical controls the default for all documents

This is a confusing feature because a.) the controls are three places (pick either View as per @Randy Hagan  or Preferences as per @Mike Witherell to restore the view) and b.) this only impacts the display of the images on screen. The images will still print as expected, no matter which setting you select.

~Barb

Click on Preferences > Display Performance > and set both Options and Adjust View Settings to High Quality Display.

Hi Hendy:

Screenshots and details really do help us help you faster. Without one or both, we are left to guess.

~Barb

Just one image or all images? Did a colour image turn to greyscale or did it turn into a grey blob?