Problem of loss of color and image

Hey Jiahu, thank you for reaching out!

From the toolbar

1. Click the Zoom/view options menu in the right corner of the toolbar.
2. Click Outlines > Show outlines.
3. Select if you’d like to Include hidden layers and Include object bounds.

Keyboard shortcut

• Press the keyboard shortcuts ⌘ Command / ControlY or ⇧ ShiftO.
• Press ⌘ Command / Control/ to search outline in the quick actions menu.