diff --git a/src/lib.rs b/src/lib.rs
index bb1273d..9a6ceaf 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -186,17 +186,6 @@ fn render_preview(state: &State) -> DynamicImage {
                 .expect("indexed color out-of-range")
                 .into()
         });
-        let mut indexed = buffer.clone();
-        for (i, pixel) in buffer.pixels().enumerate() {
-            // todo get rid of magic numbers! what about Bitsy HD?
-            let mut pixel = image::Rgba::from(pixel.0);
-            colour_map.map_color(&mut pixel);
-            indexed.put_pixel(
-                (i % 128) as u32,
-                (i / 128) as u32,
-                pixel
-            );
-        }
     }
 
     image::DynamicImage::ImageRgba8(buffer)