Font & images change colour

Doing design, I press command & Y on a Mac in error and now all my frames are purple include font, images etc…can someone help please.

You should be able to press command + Y again and return to normal.

This keyboard shortcut activates Outline Mode.

In the Keyboard Shortcuts list in the help menu, it only lists Shift + O as a way to view outlines. Command + Y is the shortcut in Adobe Illustrator, so they likely added it for people who are familiar with that, but did not add it to their list.