You can search for identifiers within the package.
in-package search v0.2.0
type t = private
| RGB of int * int * int
| ANSI of int
| ANSI256 of int
| No_color
val make : string -> t
exception Invalid_color of string
exception Invalid_color_param of string
exception Invalid_color_num of string * int
val no_color : t
val is_no_color : t -> bool
val is_rgb : t -> bool
val is_ansi : t -> bool
val is_ansi256 : t -> bool
val to_escape_seq : mode:[> `bg | `fg ] -> t -> string