"If you're on an iPhone 7 or 7 Plus, Instagram now supports wide color capture and display throughout the app—writing an eng blog on it soon"
Krieger says that an app update is not needed to get the new features.
"No update needed, rolled out to almost everyone. btw on Live Photos--try importing one in Stories and 3D-Touching screen :)"
You can download Instagram from the App Store for free.