Protect a layer
Let's continue with the second button on the right of the colors (outlined in red in the screenshot below).
This option ( ) will let you Protect with a password each Color group.
The window below will appear : enter a password and click on OK.
You will then have the Timeline below with the lockpad icon active, and it will be impossible to work on the layers in the Red group.
The icon in the Color Group panel has changed to let you know that this goup is protected. To unlock it, just click on the icon and enter your password.
Other explanations on locking layers will be given later.