diff --git a/Sources/Voxelotl/Renderer/Renderer.swift b/Sources/Voxelotl/Renderer/Renderer.swift
index 7d2a93a..25c2a9d 100644
--- a/Sources/Voxelotl/Renderer/Renderer.swift
+++ b/Sources/Voxelotl/Renderer/Renderer.swift
@@ -353,9 +353,9 @@ public class Renderer {
     var fragUniforms = FragmentShaderUniforms(
       cameraPosition: camera.position,
       directionalLight: normalize(environment.lightDirection),
-      ambientColor:  SIMD4(Color<Float>(material.ambient)),
-      diffuseColor:  SIMD4(Color<Float>(material.diffuse)),
-      specularColor: SIMD4(Color<Float>(material.specular)),
+      ambientColor:  material.ambient.reinterpretUShort,
+      diffuseColor:  material.diffuse.reinterpretUShort,
+      specularColor: material.specular.reinterpretUShort,
       specularIntensity: material.gloss)
 
     let numInstances = instances.count
@@ -384,7 +384,7 @@ public class Renderer {
           .scale(instance.scale)
         data[i] = VertexShaderInstance(
           model: model, normalModel: model.inverse.transpose,
-          color: SIMD4(Color<Float>(instance.color)))
+          color: instance.color.reinterpretUShort)
       }
     }
     instanceBuffer.didModifyRange(0..<instancesBytes)
@@ -428,6 +428,12 @@ fileprivate extension MTLCullMode {
   }
 }
 
+fileprivate extension Color where T == Float16 {
+  var reinterpretUShort: SIMD4<UInt16> {
+    .init(self.r.bitPattern, self.g.bitPattern, self.b.bitPattern, self.a.bitPattern)
+  }
+}
+
 enum RendererError: Error {
   case initFailure(_ message: String)
   case loadFailure(_ message: String)
diff --git a/Sources/Voxelotl/shader.metal b/Sources/Voxelotl/shader.metal
index ab4c6f6..db6f8be 100644
--- a/Sources/Voxelotl/shader.metal
+++ b/Sources/Voxelotl/shader.metal
@@ -45,18 +45,18 @@ fragment half4 fragmentMain(
   // Compute diffuse component
   float lambert = metal::dot(normal, lightVec);
   float diffuseAmount = metal::max(0.0, lambert);
-  half4 diffuse = half4(u.diffuseColor) * diffuseAmount;
+  half4 diffuse = u.diffuseColor * diffuseAmount;
 
   // Compute specular component (blinn-phong)
   float specularAngle = metal::max(0.0, metal::dot(halfDir, normal));
   float specularTerm = metal::pow(specularAngle, u.specularIntensity);
   // smoothstep hack to ensure highlight tapers gracefully at grazing angles
   float specularAmount = specularTerm * metal::smoothstep(0, 2, lambert * u.specularIntensity);
-  half4 specular = half4(u.specularColor) * specularAmount;
+  half4 specular = u.specularColor * specularAmount;
 
   // Sample texture & vertex color to get albedo
   half4 albedo = texture.sample(sampler, in.texCoord);
   albedo *= in.color;
 
-  return albedo * (half4(u.ambientColor) + diffuse) + specular;
+  return albedo * (u.ambientColor + diffuse) + specular;
 }
diff --git a/Sources/Voxelotl/shadertypes.h b/Sources/Voxelotl/shadertypes.h
index f316a62..fb8c84d 100644
--- a/Sources/Voxelotl/shadertypes.h
+++ b/Sources/Voxelotl/shadertypes.h
@@ -10,6 +10,13 @@
 
 #include <simd/simd.h>
 
+// HACK: allow passing SIMD4<Float16> to shader while `simd_half4` is beta
+#ifdef __METAL_VERSION__
+typedef half4 color_half4;
+#else
+typedef simd_ushort4 color_half4;
+#endif
+
 typedef NS_ENUM(NSInteger, VertexShaderInputIdx) {
   VertexShaderInputIdxVertices = 0,
   VertexShaderInputIdxInstance = 1,
@@ -25,7 +32,7 @@ typedef struct {
 typedef struct {
   matrix_float4x4 model;
   matrix_float4x4 normalModel;
-  vector_float4 color;
+  color_half4 color;
 } VertexShaderInstance;
 
 typedef struct {
@@ -38,7 +45,7 @@ typedef NS_ENUM(NSInteger, FragmentShaderInputIdx) {
 
 typedef struct {
   vector_float3 cameraPosition, directionalLight;
-  vector_float4 ambientColor, diffuseColor, specularColor;
+  color_half4 ambientColor, diffuseColor, specularColor;
   float specularIntensity;
 } FragmentShaderUniforms;