"Portable" in the context of Android APKs usually means the icon pack can be easily backed up, shared, or installed on different devices without needing to re-download it from the Google Play Store, typically by directly managing the .apk file [1].
For apps that don’t auto-theme:
Since you’re not installing permanently, you still need permission to launch the APK. Go to: Settings → Security → Install unknown apps → Allow your file manager or browser. ares colorful icon pack apk portable