--- a/MetalTexturedMesh/AAPLMathUtilities.m
+++ b/MetalTexturedMesh/AAPLMathUtilities.m
@@ -314,7 +314,7 @@ quaternion_float quaternion_slerp(quaternion_float q0, quaternion_float q1, floa
     return q0 * cosf(angleInc) + q2 * sinf(angleInc);
 }

-vector_float3 AAPL_SIMD_OVERLOAD quaternion_rotate_vector(quaternion_float q, vector_float3 v) {
+vector_float3  quaternion_rotate_vector(quaternion_float q, vector_float3 v) {

     vector_float3 qp = vector_make(q.x, q.y, q.z);
     float w = q.w;
diff --git a/MetalTexturedMesh/Renderer.swift b/MetalTexturedMesh/Renderer.swift
index 549a082..760d1e9 100644
--- a/MetalTexturedMesh/Renderer.swift
+++ b/MetalTexturedMesh/Renderer.swift
@@ -40,7 +40,7 @@ class Renderer : NSObject, MTKViewDelegate
         // Clear to solid white
         view.clearColor = MTLClearColorMake(1, 1, 1, 1)
         // Use a BGRA 8-bit normalized texture for the drawable
-        view.colorPixelFormat = .bgra8Unorm
+        view.colorPixelFormat = .bgra8Unorm_srgb
         // Use a 32-bit depth buffer
         view.depthStencilPixelFormat = .depth32Float

diff --git a/MetalTexturedMesh/Shaders.metal b/MetalTexturedMesh/Shaders.metal
index 2308954..c5ee748 100644
--- a/MetalTexturedMesh/Shaders.metal
+++ b/MetalTexturedMesh/Shaders.metal
@@ -50,15 +50,5 @@ fragment half4 fragment_lit_textured(VertexOut fragmentIn [[stage_in]],
                                      texture2d<float, access::sample> tex2d [[texture(0)]],
                                      sampler sampler2d [[sampler(0)]])
 {
-    // Sample the texture to get the surface color at this point
-    half3 surfaceColor = half3(tex2d.sample(sampler2d, fragmentIn.texCoords).rrr);
-    // Re-normalize the interpolated surface normal
-    half3 normal = normalize(half3(fragmentIn.normal));
-    // Compute the ambient color contribution
-    half3 color = ambientLightIntensity * surfaceColor;
-    // Calculate the diffuse factor as the dot product of the normal and light direction
-    float diffuseFactor = saturate(dot(normal, -lightDirection));
-    // Add in the diffuse contribution from the light
-    color += diffuseFactor * diffuseLightIntensity * surfaceColor;
-    return half4(color, 1);
+    return half4(0, 0.157, 0.202, 1);
 }
diff --git a/MetalTexturedMesh/ViewController.swift b/MetalTexturedMesh/ViewController.swift
index c286161..516d70a 100644
--- a/MetalTexturedMesh/ViewController.swift
+++ b/MetalTexturedMesh/ViewController.swift
@@ -17,7 +17,8 @@ class ViewController: NSViewController {
         super.viewDidLoad()

         let metalView = self.view as! MTKView
-
+        metalView.colorPixelFormat = .bgra8Unorm_srgb
+        NSLog("color pixel format is \(metalView.colorPixelFormat)");
         // We initialize our renderer object with the MTKView it will be drawing into
         renderer = Renderer(mtkView:metalView)
     }