diff --git a/TODO.md b/TODO.md
index 7f6a639..33f4741 100644
--- a/TODO.md
+++ b/TODO.md
@@ -5,4 +5,3 @@
 * noise reduction (remove lonely pixels)
 * implement Atkinson and Bayer dithering options
 * stats for added room (number of tiles)
-* dedupe "palette from custom colours" functionality
diff --git a/src/lib.rs b/src/lib.rs
index 4f4aa3a..41f584c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -185,19 +185,23 @@ fn image_to_base64(image: &DynamicImage) -> String {
     format!("data:image/png;base64,{}", base64::encode(&bytes))
 }
 
+fn palette_from(bg: &bitsy_parser::Colour, fg: &bitsy_parser::Colour) -> bitsy_parser::Palette {
+    bitsy_parser::Palette {
+        id: "0".to_string(),
+        name: None,
+        colours: vec![
+            bg.clone(), fg.clone(), bitsy_parser::Colour { red: 0, green: 0, blue: 0 }
+        ],
+    }
+}
+
 fn render_preview(state: &State) -> DynamicImage {
     let mut buffer = state.image.as_ref().unwrap().clone().into_rgba();
 
     let palette = match &state.palette {
         SelectedPalette::None => bitsy_parser::mock::game_default().palettes[0].clone(),
         SelectedPalette::Existing { id } => state.game.as_ref().unwrap().get_palette(id).unwrap().clone(),
-        SelectedPalette::New { background, foreground } => bitsy_parser::Palette {
-            id: "0".to_string(),
-            name: None,
-            colours: vec![
-                background.clone(), foreground.clone(), bitsy_parser::Colour { red: 0, green: 0, blue: 0 }
-            ],
-        },
+        SelectedPalette::New { background, foreground } => palette_from(background, foreground),
     };
 
     let colour_map = crate::ColourMap::from(&palette);
@@ -258,15 +262,7 @@ pub fn add_room() -> String {
         SelectedPalette::None => bitsy_parser::mock::game_default().palettes[0].id.clone(),
         SelectedPalette::Existing { id } => id.clone(),
         SelectedPalette::New { background, foreground } => {
-            game.add_palette(bitsy_parser::Palette {
-                id: "0".to_string(),
-                name: None,
-                colours: vec![
-                    background.clone(),
-                    foreground.clone(),
-                    bitsy_parser::Colour { red: 0, green: 0, blue: 0 }
-                ],
-            })
+            game.add_palette(palette_from(background, foreground))
         },
     });