These warning screens are from CBS Music Video Enterprises, Sony Music Entertainment, Sony BMG Music Entertainment and Sony Wonder. The background is blue-black gradient with the white warning text with black drop shadow and the underline.
As seen on VHS and DVD, such as Rainbow Fish episodes, Little Witch (1999), Sesame Street episodes, Elmo's World episodes, Ren and Stimpy, Hercules (1997) John Denver: The Wildlife Concert (1995) and others.
1997-1998 (KidSongs variant) Edit
These warning screens are from Sony Wonder is the same as the Warner Home Video warning.
As seen on VHS, such as KidSongs episodes.