diff --git a/crates/app/src/view.rs b/crates/app/src/view.rs
index 21743eb7..c6b55c84 100644
--- a/crates/app/src/view.rs
+++ b/crates/app/src/view.rs
@@ -571,9 +571,13 @@ impl<'a> ArrangerView<'a> {
 
 }
 
-trait ScenesColors<'a> = Iterator<Item=SceneWithColor<'a>>;
+/// Iterator over scenes with their sizes and colors.
+pub(crate) trait ScenesColors<'a> =
+    Iterator<Item=SceneWithColor<'a>>;
 
-type SceneWithColor<'a> = (usize, &'a Scene, usize, usize, Option<ItemTheme>);
+/// A scene with size and color.
+pub(crate) type SceneWithColor<'a> =
+    (usize, &'a Scene, usize, usize, Option<ItemTheme>);
 
 /// Define a type alias for iterators of sized items (columns).
 macro_rules! def_sizes_iter {