<human>: Which of the following solutions is better for the following goal:
How can you identify often used key's quickly?

OPTIONS:
- Paint the key with fingernail polish to color code -or even label with the name if you choose.
- Paint the door lock with fingernail polish to color code -or even label with the name if you choose.
<bot>: Paint the key with fingernail polish to color code -or even label with the name if you choose.