             return positive_mod(0.5 * atan2(v, u) / M_PI, 1)
         }
         set {
-            self = LuvColorModel(lightness: lightness, saturation: saturation, hue: newValue)
-        }
-    }
-    
-    public var saturation: Double {
+            self = LuvColorModel(lightness: lightness, chroma: chroma, hue: newValue)
+        }
+    }
+    
+    public var chroma: Double {
         get {
             return sqrt(u * u + v * v)
         }
         set {
-            self = LuvColorModel(lightness: lightness, saturation: newValue, hue: hue)
+            self = LuvColorModel(lightness: lightness, chroma: newValue, hue: hue)
         }
     }
 }

        self.a = a
        self.b = b
    }
    public init(lightness: Double, saturation: Double, hue: Double) {
        self.lightness = lightness
        self.a = saturation * cos(2 * M_PI * hue)
        self.b = saturation * sin(2 * M_PI * hue)
    }
}


        self.u = u
        self.v = v
    }
    public init(lightness: Double, chroma: Double, hue: Double) {
        self.lightness = lightness
        self.u = chroma * cos(2 * M_PI * hue)
        self.v = chroma * sin(2 * M_PI * hue)
    }
}

