It's a new feature, and app developers need to implement it. Leave a review or a message to the app developer asking for the feature.
Source: am Android app developer
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It's a new feature, and app developers need to implement it. Leave a review or a message to the app developer asking for the feature.
Source: am Android app developer
Alternatively, you can use an icon app that'll "force" it such as icon studio etc.
This is what I do. I use Kvaesitso and it is a search based launcher that has a setting to force material you icon theming that usually works well. Other than that I am not sure how you would force it with the regular android launchers
You'll have to use a 3rd party launcher and/or a custom icon pack if you want consistency beyond what the app developers have provided
Basically not all apps support it. The developer of the app must update his app to support it.
Secondly there are icon packs you can buy where the dev of the icons manually created all of them. But even there, some apps will still be in their normal colour because he hasn't made an icon for that app yet.
Most people just remove the apps from the home screen and leave only the themed apps
nova launcher mabye
You will need an icon pack and/or a 3rd party launcher application. Pix Material You Light/Dark(paid) should fit the bill. Smart launcher 6 also has an option for themed icons.