diff --git a/src/main/java/eu/jonahbauer/raytracing/math/IVec.java b/src/main/java/eu/jonahbauer/raytracing/math/IVec.java
index 0aad0da..3e5497f 100644
--- a/src/main/java/eu/jonahbauer/raytracing/math/IVec.java
+++ b/src/main/java/eu/jonahbauer/raytracing/math/IVec.java
@@ -1,5 +1,6 @@
 package eu.jonahbauer.raytracing.math;
 
+import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
 
 /**
@@ -7,15 +8,26 @@ import org.jetbrains.annotations.NotNull;
  * @param <T> the type
  */
 public interface IVec<T extends IVec<T>> {
+    @Contract(pure = true)
     double get(int i);
 
+    @Contract(pure = true)
     @NotNull T plus(@NotNull T other);
+
+    @Contract(pure = true)
     @NotNull T minus(@NotNull T other);
+
+    @Contract(pure = true)
     @NotNull T times(@NotNull T other);
+
+    @Contract(pure = true)
     @NotNull T times(double d);
+
+    @Contract(pure = true)
     default @NotNull T div(double d) {
         return times(1 / d);
     }
 
+    @Contract(pure = true)
     double @NotNull[] toArray();
 }
diff --git a/src/main/java/eu/jonahbauer/raytracing/math/IVec3.java b/src/main/java/eu/jonahbauer/raytracing/math/IVec3.java
index c1bff7f..c3f4f52 100644
--- a/src/main/java/eu/jonahbauer/raytracing/math/IVec3.java
+++ b/src/main/java/eu/jonahbauer/raytracing/math/IVec3.java
@@ -1,5 +1,6 @@
 package eu.jonahbauer.raytracing.math;
 
+import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
 
 /**
@@ -7,17 +8,23 @@ import org.jetbrains.annotations.NotNull;
  * @param <T> the type
  */
 public interface IVec3<T extends Record & IVec3<T>> extends IVec<T> {
+    @Contract(pure = true)
     default double component1() {
         return toVec3().x();
     }
+
+    @Contract(pure = true)
     default double component2() {
         return toVec3().y();
     }
+
+    @Contract(pure = true)
     default double component3() {
         return toVec3().z();
     }
 
     @Override
+    @Contract(pure = true)
     default double get(int i) {
         return switch (i) {
             case 0 -> component1();
@@ -27,9 +34,13 @@ public interface IVec3<T extends Record & IVec3<T>> extends IVec<T> {
         };
     }
 
-    @NotNull Vec3 toVec3();
+    @Contract(pure = true)
+    default @NotNull Vec3 toVec3() {
+        return new Vec3(component1(), component2(), component3());
+    }
 
     @Override
+    @Contract(pure = true)
     default double @NotNull [] toArray() {
         return new double[] {component1(), component2(), component3()};
     }
diff --git a/src/main/java/eu/jonahbauer/raytracing/render/spectral/SampledWavelengths.java b/src/main/java/eu/jonahbauer/raytracing/render/spectral/SampledWavelengths.java
index 18374d0..1621abb 100644
--- a/src/main/java/eu/jonahbauer/raytracing/render/spectral/SampledWavelengths.java
+++ b/src/main/java/eu/jonahbauer/raytracing/render/spectral/SampledWavelengths.java
@@ -3,6 +3,7 @@ package eu.jonahbauer.raytracing.render.spectral;
 import eu.jonahbauer.raytracing.render.spectral.colors.ColorXYZ;
 import eu.jonahbauer.raytracing.render.spectral.spectrum.Spectra;
 import eu.jonahbauer.raytracing.render.spectral.spectrum.Spectrum;
+import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Arrays;
@@ -46,10 +47,12 @@ public final class SampledWavelengths {
         this.pdf = pdf;
     }
 
+    @Contract(pure = true)
     public double get(int index) {
         return lambdas[index];
     }
 
+    @Contract(pure = true)
     public int size() {
         return lambdas.length;
     }
@@ -58,6 +61,7 @@ public final class SampledWavelengths {
      * Terminates the secondary wavelengths. This method should be called after a wavelength-dependent operation like
      * refraction that makes it incorrect to track multiple wavelengths together.
      */
+    @Contract(mutates = "this")
     public double collapse() {
         if (pdf.length >= 2 || pdf[1] != 0) {
             Arrays.fill(pdf, 1, pdf.length, 0d);
diff --git a/src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorRGB.java b/src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorRGB.java
index 3013e96..28f0af5 100644
--- a/src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorRGB.java
+++ b/src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorRGB.java
@@ -1,13 +1,10 @@
 package eu.jonahbauer.raytracing.render.spectral.colors;
 
 import eu.jonahbauer.raytracing.math.IVec3;
-import eu.jonahbauer.raytracing.math.Vec3;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Random;
 
-import static eu.jonahbauer.raytracing.Main.DEBUG;
-
 public record ColorRGB(double r, double g, double b) implements IVec3<ColorRGB> {
     public static final @NotNull ColorRGB BLACK = new ColorRGB(0.0, 0.0, 0.0);
     public static final @NotNull ColorRGB WHITE = new ColorRGB(1.0, 1.0, 1.0);
@@ -34,9 +31,9 @@ public record ColorRGB(double r, double g, double b) implements IVec3<ColorRGB>
     }
 
     public ColorRGB {
-        if (DEBUG && (!Double.isFinite(r) || !Double.isFinite(g) || !Double.isFinite(b))) {
-            throw new IllegalArgumentException("r, g and b must be finite");
-        }
+        assert Double.isFinite(r) : "r must be finite";
+        assert Double.isFinite(g) : "g must be finite";
+        assert Double.isFinite(b) : "b must be finite";
     }
 
     /*
@@ -103,19 +100,6 @@ public record ColorRGB(double r, double g, double b) implements IVec3<ColorRGB>
         return new ColorRGB(r * other.r, g * other.g, b * other.b);
     }
 
-    /*
-     * Vec3
-     */
-
-    @Override
-    public @NotNull Vec3 toVec3() {
-        return new Vec3(r, g, b);
-    }
-
-    public static @NotNull ColorRGB fromVec3(@NotNull Vec3 vec) {
-        return new ColorRGB(vec.x(), vec.y(), vec.z());
-    }
-
     /*
      * Accessors
      */
diff --git a/src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorSpace.java b/src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorSpace.java
index f281136..4fb5629 100644
--- a/src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorSpace.java
+++ b/src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorSpace.java
@@ -61,7 +61,7 @@ public final class ColorSpace {
 
     public @NotNull ColorXYZ toXYZ(@NotNull ColorRGB rgb) {
         var out = XYZfromRGB.times(rgb.toVec3());
-        return ColorXYZ.fromVec3(out);
+        return new ColorXYZ(out);
     }
 
     public @NotNull Vec3 toCIELab(@NotNull ColorRGB rgb) {
diff --git a/src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorXYZ.java b/src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorXYZ.java
index c015e1b..4e9bbf7 100644
--- a/src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorXYZ.java
+++ b/src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorXYZ.java
@@ -25,6 +25,16 @@ public record ColorXYZ(double x, double y, double z) implements IVec3<ColorXYZ>
         );
     }
 
+    public ColorXYZ(@NotNull Vec3 vec) {
+        this(vec.x(), vec.y(), vec.z());
+    }
+
+    public ColorXYZ {
+        assert Double.isFinite(x) : "x must be finite";
+        assert Double.isFinite(y) : "y must be finite";
+        assert Double.isFinite(z) : "z must be finite";
+    }
+
     /*
      * Math
      */
@@ -71,19 +81,6 @@ public record ColorXYZ(double x, double y, double z) implements IVec3<ColorXYZ>
         return new ColorXYZ(x * d, y * d, z * d);
     }
 
-    /*
-     * Vec3
-     */
-
-    @Override
-    public @NotNull Vec3 toVec3() {
-        return new Vec3(x, y, z);
-    }
-
-    public static @NotNull ColorXYZ fromVec3(@NotNull Vec3 vec) {
-        return new ColorXYZ(vec.x(), vec.y(), vec.z());
-    }
-
     /*
      * Accessors
      */