Added some comments.

oklab.go

@@ -170,6 +170,9 @@ func sqr(a float64) float64 {
 	return a * a
 }
 
+// Distance returns the perceptual distance between two colors.
+//
+// This controls for possible transparency. Two different but otherwise fully transparent colors would have a distance of zero.
 func Distance(a, b Color) float64 {
 	L1, a1, b1 := a.Lightness*a.A, a.ChromaA*a.A, a.ChromaB*a.A
 	L2, a2, b2 := b.Lightness*b.A, b.ChromaA*b.A, b.ChromaB*b.A
@@ -186,6 +189,8 @@ func okLabModel(c color.Color) color.Color {
 
 var (
 	// A color model for converting arbitrary colors to OKLab.
+	//
+	// Wraps the [FromColor] function, returning a [color.Color] interface rather than the [Color] type.
 	Model = color.ModelFunc(okLabModel)
 
 	// Type assertions.