My depth effect does not highlight yellow what will I do

Are you asking about Portrait Mode photos on an iPhone? Are you trying to work with Portrait Mode photos in iPhoto on a Mac, as your question is in the iPhoto Forum?

iPhoto is too old to and has not been updated for several years, so it cannot handle Portrait Mode photos. On a Mac you should be using Photos for Mac, the successor of iPhoto, to be able to edit Portrait Mode photos.

You can only use Portrait Lighting on iPhone models that support it - see this list: models that support Portrait Lighting

Your iPhone 7 Plus is not compatible.

Models that support Portrait Lighting

• iPhone SE (2nd generation)

• iPhone 12 Mini
• iPhone 12
• iPhone 12 Pro
• iPhone 12 Pro Max
• iPhone SE (2nd generation)
• iPhone 11
• iPhone 11 Pro
• iPhone 11 Pro Max
• iPhone XR
• iPhone XS
• iPhone XS Max
• iPhone X
• iPhone 8 Plus

From: Edit Portrait mode photos on iPhone - Apple Support

Is the device model given below your question still valid? iPhone 7 Plus, also the system version  iOS 13?