gray, grayed out

Most of the time, talk about the actions that customers should take.

Don’t use gray or grayed out to describe commands or options that are in an unusable state—use not available or isn’t available instead. Use appears dimmed if you must describe their appearance. Use shaded to describe the appearance of checkboxes that represent a mixture of settings.

Examples
The command isn’t available until you select text.
If the option appears dimmed, it's not available.
Selected effects appear shaded.

See also disable, disabled, unavailable