diff --git a/crates/raw/src/spectral.rs b/crates/raw/src/spectral.rs
--- a/crates/raw/src/spectral.rs
+++ b/crates/raw/src/spectral.rs
@@ -44,7 +44,8 @@ impl Camera {
 /// `(make, model as sold, table model)`: bodies sharing a table camera's sensor that rawtoaces-data's alias list
 /// doesn't name, kept here because the table is generated. Fujifilm's 26.1 MP X-Trans CMOS 4 bodies use the X-T3's
 /// sensor (X-T30 issue: a black-and-white Acros camera JPEG gives no colour to fit, and without matrices the photo
-/// opened in the muted neutral fallback).
+/// opened in the muted neutral fallback). The GFX100S II uses the GFX 100's sensor, so it borrows its matrices
+/// (without them its raws fall back to the neutral camera-RGB-approximately-sRGB colour, which shifts hues).
 const SAME_SENSOR: &[(&str, &str, &str)] = &[
     ("Fujifilm", "X-T30", "X-T3"),
     ("Fujifilm", "X-T30 II", "X-T3"),
@@ -52,6 +53,7 @@ const SAME_SENSOR: &[(&str, &str, &str)] = &[
     ("Fujifilm", "X100V", "X-T3"),
     ("Fujifilm", "X-S10", "X-T3"),
     ("Fujifilm", "X-E4", "X-T3"),
+    ("Fujifilm", "GFX100S II", "GFX 100"),
 ];
 
 /// Model names compared without case, the brand, a leading `EOS` or a trailing `DIGITAL`
@@ -169,6 +171,13 @@ mod tests {
         }
     }
 
+    #[test]
+    fn gfx100s_ii_uses_gfx_100_matrices() {
+        // GFX100S II is not in the table, so its raws never get step 4's measured matrices
+        // and fall back to step 5's neutral camera-RGB-approximately-sRGB.
+        assert_eq!(find(Some("FUJIFILM"), "GFX100S II").map(|c| c.model), Some("GFX 100"),);
+    }
+
     #[test]
     fn other_cameras_and_other_makes_find_nothing() {
         assert_eq!(find(Some("Canon"), "Canon EOS 7D"), None);