diff --git a/utils/depth.go b/utils/depth.go
deleted file mode 100644
index 0bb051b..0000000
--- a/utils/depth.go
+++ /dev/null
@@ -1,36 +0,0 @@
-package utils
-
-import "image/color"
-
-func ColorModel(depth int) color.Model {
-	switch depth {
-	case 8:
-		return color.GrayModel
-	case 24, 32:
-		return color.RGBAModel
-	default:
-		return color.Gray16Model
-	}
-}
-
-func WhiteColor(depth int) color.Color {
-	switch depth {
-	case 8:
-		return color.Gray{Y: 255}
-	case 24, 32:
-		return color.RGBA{255, 255, 255, 255}
-	default:
-		return color.White
-	}
-}
-
-func BlackColor(depth int) color.Color {
-	switch depth {
-	case 8:
-		return color.Gray{Y: 0}
-	case 24, 32:
-		return color.RGBA{0, 0, 0, 255}
-	default:
-		return color.Black
-	}
-}