What Verified Boot actually tells you

Android Verified Boot (AVB 2.0) reports one of a small number of states, and it's easy to treat that state as a pass/fail signal when it's really describing something more specific: whether the chain from boot ROM to boot image to system image is intact and matches what the device's owner (or manufacturer) has told it to trust.

"Green" means every stage in the chain verified against keys the device trusts out of the box — nothing has been modified. "Yellow" means the device is still verifying successfully, but against a custom key the user explicitly enrolled — a deliberate, disclosed change, not a compromise. "Orange" means verification is off entirely, usually because the bootloader is unlocked. "Red" is the one that actually means something failed to verify.

The reason this distinction matters in a repair or diagnostic context: an unlocked bootloader (orange) and a genuinely tampered boot chain (red) look similar from a distance — "not stock" — but they mean completely different things for what you should do next. Treating them the same way is how avoidable mistakes happen.

UnlockLab reports the actual AVB state as the device presents it, labeled plainly, specifically so that distinction doesn't get lost between what the device is telling you and what ends up in your notes.