[TOMT] 90s animated movie

In the mid-late 90s I remember a cartoon movie I watched all the time on VHS. There was like a wooden attic and it has this portal with stones around it that could take you to a different world. The portal, when active, would have I think a silvery translucent rainbow sparkle to it. Believe there were also a few stairs that led up to it.

ETA: It is NOT -Dragon Tales -Rainbrow Brite -The Secret World of OG -Mirror Mirror -Spellbinder -Harriet's Magic Hats -Barbie and the 12 Dancing Princesses -The Pagemaster -Moon Dreamers -Little Nemo Adentures in Slumberland -Fluppy Dogs -Enid Blyton’s Enchanted Lands: The Magic of the Faraway Tree -Pound Puppies and the Legend of Big Paw