diff --git a/README.md b/README.md
index e640501..55ba39c 100644
--- a/README.md
+++ b/README.md
@@ -14,11 +14,17 @@ Fun & easy way to create _color gradient_ / _color scales_ in __Go__ (__Golang__
 * [Usages](#usages)
   - [Basic](#basic)
   - [Custom Colors](#custom-colors)
+  - [Hex Colors](#using-hex-colors)
+  - [Custom Domain](#custom-domain)
+  - [Blending Mode](#blending-mode)
+  - [Invalid RGB](#beware-of-invalid-rgb-color)
+  - [Hard-Edged Gradient](#hard-edged-gradient)
 * [Preset Gradients](#preset-gradients)
 * [Color Scheme](#color-scheme)
-* [Random Colors](#random-colors)
-* [Playground](#go-playground)
+* [Gallery](#gallery)
+* [Playground](#playground)
 * [Dependencies](#dependencies)
+* [Inspirations](#inspirations)
 
 ### Usages
 
@@ -119,6 +125,20 @@ Without `Clamped()`
 With `Clamped()`
 ![valid rgb](img/clamped.png)
 
+#### Hard-Edged Gradient
+
+```go
+grad1, err := colorgrad.NewGradient().
+    HexColors("#18dbf4", "#f6ff56").
+    Build()
+```
+![img](img/normal-gradient.png)
+
+```go
+grad2 := colorgrad.SharpGradient(grad1, 7)
+```
+![img](img/classes-gradient.png)
+
 ### Preset Gradients
 
 ```go
@@ -218,11 +238,15 @@ grad, err := colorgrad.NewGradient().
 `colorgrad.Scheme.Set3`
 ![img](img/scheme-set3.png)
 
-### Random Colors
+### Gallery
+
+Colored noise using hard-edged gradient.
+![noise](img/noise-2.png)
 
+Random colors using `colorgrad.Cool()`.
 ![random-color](img/random-cool.png)
 
-### Go Playground
+### Playground
 
 * [Basic](https://play.golang.org/p/rE8OI50PsQA)
 * [Random colors](https://play.golang.org/p/d67x9di4sAF)
diff --git a/gradset.go b/gradset.go
index f0938ea..907b84e 100644
--- a/gradset.go
+++ b/gradset.go
@@ -1,39 +1,73 @@
 package colorgrad
 
-func Viridis() Gradient {
-	colors := []string{"#440154", "#482777", "#3f4a8a", "#31678e", "#26838f", "#1f9d8a", "#6cce5a", "#b6de2b", "#fee825"}
+// Diverging
+
+func BrBG() Gradient {
+	colors := []string{"#543005", "#8c510a", "#bf812d", "#dfc27d", "#f6e8c3", "#f5f5f5", "#c7eae5", "#80cdc1", "#35978f", "#01665e", "#003c30"}
 	grad, _ := NewGradient().
 		HexColors(colors...).
 		Build()
 	return grad
 }
 
-func Spectral() Gradient {
-	colors := []string{"#9e0142", "#d53e4f", "#f46d43", "#fdae61", "#fee08b", "#ffffbf", "#e6f598", "#abdda4", "#66c2a5", "#3288bd", "#5e4fa2"}
+func PRGn() Gradient {
+	colors := []string{"#40004b", "#762a83", "#9970ab", "#c2a5cf", "#e7d4e8", "#f7f7f7", "#d9f0d3", "#a6dba0", "#5aae61", "#1b7837", "#00441b"}
 	grad, _ := NewGradient().
 		HexColors(colors...).
 		Build()
 	return grad
 }
 
-func Plasma() Gradient {
-	colors := []string{"#0d0887", "#42039d", "#6a00a8", "#900da3", "#b12a90", "#cb4678", "#e16462", "#f1834b", "#fca636", "#fccd25", "#f0f921"}
+func PiYG() Gradient {
+	colors := []string{"#8e0152", "#c51b7d", "#de77ae", "#f1b6da", "#fde0ef", "#f7f7f7", "#e6f5d0", "#b8e186", "#7fbc41", "#4d9221", "#276419"}
 	grad, _ := NewGradient().
 		HexColors(colors...).
 		Build()
 	return grad
 }
 
-func Magma() Gradient {
-	colors := []string{"#000004", "#140e37", "#3b0f70", "#641a80", "#8c2981", "#b63679", "#de4968", "#f66f5c", "#fe9f6d", "#fece91", "#fcfdbf"}
+func PuOr() Gradient {
+	colors := []string{"#7f3b08", "#b35806", "#e08214", "#fdb863", "#fee0b6", "#f7f7f7", "#d8daeb", "#b2abd2", "#8073ac", "#542788", "#2d004b"}
 	grad, _ := NewGradient().
 		HexColors(colors...).
 		Build()
 	return grad
 }
 
-func Inferno() Gradient {
-	colors := []string{"#000004", "#170b3a", "#420a68", "#6b176e", "#932667", "#bb3654", "#dd513a", "#f3771a", "#fca50a", "#f6d644", "#fcffa4"}
+func RdBu() Gradient {
+	colors := []string{"#67001f", "#b2182b", "#d6604d", "#f4a582", "#fddbc7", "#f7f7f7", "#d1e5f0", "#92c5de", "#4393c3", "#2166ac", "#053061"}
+	grad, _ := NewGradient().
+		HexColors(colors...).
+		Build()
+	return grad
+}
+
+func RdGy() Gradient {
+	colors := []string{"#67001f", "#b2182b", "#d6604d", "#f4a582", "#fddbc7", "#ffffff", "#e0e0e0", "#bababa", "#878787", "#4d4d4d", "#1a1a1a"}
+	grad, _ := NewGradient().
+		HexColors(colors...).
+		Build()
+	return grad
+}
+
+func RdYlBu() Gradient {
+	colors := []string{"#a50026", "#d73027", "#f46d43", "#fdae61", "#fee090", "#ffffbf", "#e0f3f8", "#abd9e9", "#74add1", "#4575b4", "#313695"}
+	grad, _ := NewGradient().
+		HexColors(colors...).
+		Build()
+	return grad
+}
+
+func RdYlGn() Gradient {
+	colors := []string{"#a50026", "#d73027", "#f46d43", "#fdae61", "#fee08b", "#ffffbf", "#d9ef8b", "#a6d96a", "#66bd63", "#1a9850", "#006837"}
+	grad, _ := NewGradient().
+		HexColors(colors...).
+		Build()
+	return grad
+}
+
+func Spectral() Gradient {
+	colors := []string{"#9e0142", "#d53e4f", "#f46d43", "#fdae61", "#fee08b", "#ffffbf", "#e6f598", "#abdda4", "#66c2a5", "#3288bd", "#5e4fa2"}
 	grad, _ := NewGradient().
 		HexColors(colors...).
 		Build()
@@ -88,3 +122,37 @@ func Reds() Gradient {
 		Build()
 	return grad
 }
+
+// Sequential (Multi-Hue)
+
+func Viridis() Gradient {
+	colors := []string{"#440154", "#482777", "#3f4a8a", "#31678e", "#26838f", "#1f9d8a", "#6cce5a", "#b6de2b", "#fee825"}
+	grad, _ := NewGradient().
+		HexColors(colors...).
+		Build()
+	return grad
+}
+
+func Inferno() Gradient {
+	colors := []string{"#000004", "#170b3a", "#420a68", "#6b176e", "#932667", "#bb3654", "#dd513a", "#f3771a", "#fca50a", "#f6d644", "#fcffa4"}
+	grad, _ := NewGradient().
+		HexColors(colors...).
+		Build()
+	return grad
+}
+
+func Magma() Gradient {
+	colors := []string{"#000004", "#140e37", "#3b0f70", "#641a80", "#8c2981", "#b63679", "#de4968", "#f66f5c", "#fe9f6d", "#fece91", "#fcfdbf"}
+	grad, _ := NewGradient().
+		HexColors(colors...).
+		Build()
+	return grad
+}
+
+func Plasma() Gradient {
+	colors := []string{"#0d0887", "#42039d", "#6a00a8", "#900da3", "#b12a90", "#cb4678", "#e16462", "#f1834b", "#fca636", "#fccd25", "#f0f921"}
+	grad, _ := NewGradient().
+		HexColors(colors...).
+		Build()
+	return grad
+}
diff --git a/gradset_test.go b/gradset_test.go
index d0779ef..9589c49 100644
--- a/gradset_test.go
+++ b/gradset_test.go
@@ -5,11 +5,15 @@ import (
 )
 
 func TestPreset(t *testing.T) {
-	testGrad(t, Inferno(), "#000004", "#fcffa4")
-	testGrad(t, Magma(), "#000004", "#fcfdbf")
-	testGrad(t, Plasma(), "#0d0887", "#f0f921")
+	testGrad(t, BrBG(), "#543005", "#003c30")
+	testGrad(t, PRGn(), "#40004b", "#00441b")
+	testGrad(t, PiYG(), "#8e0152", "#276419")
+	testGrad(t, PuOr(), "#7f3b08", "#2d004b")
+	testGrad(t, RdBu(), "#67001f", "#053061")
+	testGrad(t, RdGy(), "#67001f", "#1a1a1a")
+	testGrad(t, RdYlBu(), "#a50026", "#313695")
+	testGrad(t, RdYlGn(), "#a50026", "#006837")
 	testGrad(t, Spectral(), "#9e0142", "#5e4fa2")
-	testGrad(t, Viridis(), "#440154", "#fee825")
 
 	testGrad(t, Blues(), "#f7fbff", "#08306b")
 	testGrad(t, Greens(), "#f7fcf5", "#00441b")
@@ -17,6 +21,11 @@ func TestPreset(t *testing.T) {
 	testGrad(t, Oranges(), "#fff5eb", "#7f2704")
 	testGrad(t, Purples(), "#fcfbfd", "#3f007d")
 	testGrad(t, Reds(), "#fff5f0", "#67000d")
+
+	testGrad(t, Viridis(), "#440154", "#fee825")
+	testGrad(t, Inferno(), "#000004", "#fcffa4")
+	testGrad(t, Magma(), "#000004", "#fcfdbf")
+	testGrad(t, Plasma(), "#0d0887", "#f0f921")
 }
 
 func testGrad(t *testing.T, grad Gradient, start, end string) {
diff --git a/gradx.go b/gradx.go
index bbb9fce..68b428a 100644
--- a/gradx.go
+++ b/gradx.go
@@ -7,42 +7,42 @@ import (
 	"github.com/lucasb-eyer/go-colorful"
 )
 
-type classesGrad struct {
+type sharpGradient struct {
 	colors []colorful.Color
 	pos    []float64
 	n      int
 }
 
-func Classes(grad Gradient, count uint) Gradient {
-	return classesGrad{
+func SharpGradient(grad Gradient, count uint) Gradient {
+	return sharpGradient{
 		colors: grad.Colors(count),
 		pos:    linspace(0, 1, count+1),
 		n:      int(count),
 	}
 }
 
-func (cg classesGrad) At(t float64) colorful.Color {
+func (sg sharpGradient) At(t float64) colorful.Color {
 	if math.IsNaN(t) || t < 0 {
-		return cg.colors[0]
+		return sg.colors[0]
 	}
 
 	if t > 1 {
-		return cg.colors[cg.n-1]
+		return sg.colors[sg.n-1]
 	}
 
-	for i := 0; i < cg.n; i++ {
-		if (cg.pos[i] <= t) && (t <= cg.pos[i+1]) {
-			return cg.colors[i]
+	for i := 0; i < sg.n; i++ {
+		if (sg.pos[i] <= t) && (t <= sg.pos[i+1]) {
+			return sg.colors[i]
 		}
 	}
-	return cg.colors[cg.n-1]
+	return sg.colors[sg.n-1]
 }
 
-func (cg classesGrad) Colors(count uint) []colorful.Color {
+func (sg sharpGradient) Colors(count uint) []colorful.Color {
 	l := float64(count - 1)
 	colors := make([]colorful.Color, count)
 	for i := range colors {
-		colors[i] = cg.At(float64(i) / l)
+		colors[i] = sg.At(float64(i) / l)
 	}
 	return colors
 }
diff --git a/gradx_test.go b/gradx_test.go
index ffe22ca..5fe0d5a 100644
--- a/gradx_test.go
+++ b/gradx_test.go
@@ -8,7 +8,7 @@ import (
 
 func TestX(t *testing.T) {
 	grad, _ := NewGradient().Build()
-	grad2 := Classes(grad, 7)
+	grad2 := SharpGradient(grad, 7)
 	testStr(t, grad2.At(0).Hex(), "#000000")
 	testStr(t, grad2.At(1).Hex(), "#ffffff")
 
diff --git a/img/classes-gradient.png b/img/classes-gradient.png
new file mode 100644
index 0000000..0e4f664
Binary files /dev/null and b/img/classes-gradient.png differ
diff --git a/img/noise-2.png b/img/noise-2.png
new file mode 100644
index 0000000..8776fd2
Binary files /dev/null and b/img/noise-2.png differ
diff --git a/img/normal-gradient.png b/img/normal-gradient.png
new file mode 100644
index 0000000..fc45d1d
Binary files /dev/null and b/img/normal-gradient.png differ