diff --git a/app-proto/inversive-display/src/inversive.frag b/app-proto/inversive-display/src/inversive.frag
index fbb60f6..7eb16b5 100644
--- a/app-proto/inversive-display/src/inversive.frag
+++ b/app-proto/inversive-display/src/inversive.frag
@@ -173,11 +173,17 @@ void main() {
     if (debug_mode) {
         // at the bottom of the screen, show the color scale instead of the
         // layer count
-        if (gl_FragCoord.y < 10.) layer_cnt = int(8. * gl_FragCoord.x / resolution.x);
+        if (gl_FragCoord.y < 10.) layer_cnt = 2 * int(8. * gl_FragCoord.x / resolution.x);
         
         // convert number to color
-        ivec3 bits = layer_cnt / ivec3(1, 2, 4);
-        outColor = vec4(mod(vec3(bits), 2.), 1.);
+        vec3 color;
+        if (layer_cnt % 2 == 0) {
+            ivec3 bits = layer_cnt / ivec3(2, 4, 8);
+            color = mod(vec3(bits), 2.);
+        } else {
+            color = vec3(0.5);
+        }
+        outColor = vec4(color, 1.);
         return;
     }
     
diff --git a/app-proto/inversive-display/src/main.rs b/app-proto/inversive-display/src/main.rs
index 1855ce2..f5b42c5 100644
--- a/app-proto/inversive-display/src/main.rs
+++ b/app-proto/inversive-display/src/main.rs
@@ -132,7 +132,10 @@ fn main() {
             let color_vec = vec![
                 [1.00_f32, 0.25_f32, 0.00_f32],
                 [0.00_f32, 0.25_f32, 1.00_f32],
-                [0.25_f32, 0.00_f32, 1.00_f32]
+                [0.25_f32, 0.00_f32, 1.00_f32],
+                [0.25_f32, 1.00_f32, 0.00_f32],
+                [0.75_f32, 0.75_f32, 0.00_f32],
+                [0.00_f32, 0.75_f32, 0.50_f32],
             ];
             
             // timing
@@ -292,6 +295,9 @@ fn main() {
                     sphere_vec.push(&construction_to_world * engine::sphere(0.5, 0.5, ctrl_x.get(), radius_x.get()));
                     sphere_vec.push(&construction_to_world * engine::sphere(-0.5, -0.5, ctrl_y.get(), radius_y.get()));
                     sphere_vec.push(&construction_to_world * engine::sphere(-0.5, 0.5, 0.0, 0.75));
+                    sphere_vec.push(&construction_to_world * engine::sphere(0.5, -0.5, 0.0, 0.5));
+                    sphere_vec.push(&construction_to_world * engine::sphere(0.0, 0.15, 1.0, 0.25));
+                    sphere_vec.push(&construction_to_world * engine::sphere(0.0, -0.15, -1.0, 0.25));
                     
                     // set the resolution
                     let width = canvas.width() as f32;