Oracle 18c

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
create table toys (
  name varchar2(10),
  weight number,
  color varchar2(10),
  PRIMARY KEY (name)
)
partition by list (color)  (
  partition p_green VALUES('green'),
  partition p_red VALUES('red')
);
INSERT INTO toys
VALUES ('a', 1, 'blue')
ORA-14400: inserted partition key does not map to any partition

create table toys2 (
  name varchar2(10),
  weight number,
  color varchar2(10),
  PRIMARY KEY (name)
)
partition by list (color)  AUTOMATIC (
  partition p_green VALUES('green'),
  partition p_red VALUES('red')
);
INSERT INTO toys2
VALUES ('a', 1, 'blue')
1 rows affected

create table toys3 (
  name varchar2(10),
  weight number,
  color varchar2(10),
  PRIMARY KEY (name)
)
partition by list (color)   (
  partition p_green VALUES('green'),
  partition p_red VALUES('red'),
  partition p_def VALUES (DEFAULT)
);
INSERT INTO toys3
VALUES ('a', 1, 'blue')
1 rows affected