Unreal Engine 5.0.1 - 3D game objects displayed in orange colour

Question

I downloaded Unreal Engine 5.0.1 recently and created an RPG project. But once the project loaded,

• the playground and every other object in it were orange in colour;

• and the player didn't show up on the screen either. The player was only visible in the "Play" mode, but it was orange in colour too.

see viewport image here

The only way I could see the player or any other material in its original grey colour was when I double-clicked on them in the content folder and viewed them separately.

see player's viewport image here

I checked to see if the material colours of the objects are orange too. But they were all shades of grey.

I tried adding a new cube and it came out white (not orange). Then I replaced its material with the other grey colour materials available in the project. The only thing that changed was the material texture of the object. The colour switched back to orange again.

I checked and unchecked all the things in the "show" menu, but it didn't help either.

This was the very first project I created right after I downloaded Unreal Engine. None of the default settings was changed.

How can I make the player visible, and how do I get the orange colour to change back to the original grey colour?