diff --git a/example/game/input/input.go b/example/game/input/input.go
index 0d3e8f245..4619d668c 100644
--- a/example/game/input/input.go
+++ b/example/game/input/input.go
@@ -26,7 +26,6 @@ import (
 	"github.com/hajimehoshi/go.ebiten/graphics"
 	"github.com/hajimehoshi/go.ebiten/graphics/matrix"
 	"image"
-	"image/color"
 	"os"
 )
 
@@ -60,7 +59,7 @@ func (game *Input) Update(context ebiten.GameContext) {
 }
 
 func (game *Input) Draw(g graphics.Context) {
-	g.Fill(&color.RGBA{R: 128, G: 128, B: 255, A: 255})
+	g.Fill(128, 128, 255)
 	str := fmt.Sprintf(`Input State:
   X: %d
   Y: %d`, game.inputState.X, game.inputState.Y)
diff --git a/example/game/monochrome/monochrome.go b/example/game/monochrome/monochrome.go
index 4d6d75965..768f09ee1 100644
--- a/example/game/monochrome/monochrome.go
+++ b/example/game/monochrome/monochrome.go
@@ -25,7 +25,6 @@ import (
 	"github.com/hajimehoshi/go.ebiten/graphics"
 	"github.com/hajimehoshi/go.ebiten/graphics/matrix"
 	"image"
-	"image/color"
 	_ "image/png"
 	"os"
 )
@@ -116,7 +115,7 @@ func (game *Monochrome) Update(context ebiten.GameContext) {
 }
 
 func (game *Monochrome) Draw(g graphics.Context) {
-	g.Fill(&color.RGBA{R: 128, G: 128, B: 255, A: 255})
+	g.Fill(128, 128, 255)
 
 	g.DrawTexture(game.ebitenTexture.ID(),
 		game.geometryMatrix, game.colorMatrix)
diff --git a/example/game/rects/rects.go b/example/game/rects/rects.go
index c82280ccc..fe90ba04f 100644
--- a/example/game/rects/rects.go
+++ b/example/game/rects/rects.go
@@ -95,13 +95,13 @@ func (game *Rects) rectColorMatrix() matrix.Color {
 func (game *Rects) Draw(g graphics.Context) {
 	if !game.rectTextureInited {
 		g.SetOffscreen(game.rectTexture.ID())
-		g.Fill(&color.White)
+		g.Fill(255, 255, 255)
 		game.rectTextureInited = true
 	}
 
 	g.SetOffscreen(game.offscreen.ID())
 	if !game.offscreenInited {
-		g.Fill(&color.RGBA{0, 0, 0, 255})
+		g.Fill(0, 0, 0)
 		game.offscreenInited = true
 	}
 	g.DrawTexture(game.rectTexture.Texture().ID(),
diff --git a/example/game/rotating/rotating.go b/example/game/rotating/rotating.go
index 917767ef0..c53ca5d98 100644
--- a/example/game/rotating/rotating.go
+++ b/example/game/rotating/rotating.go
@@ -25,7 +25,6 @@ import (
 	"github.com/hajimehoshi/go.ebiten/graphics"
 	"github.com/hajimehoshi/go.ebiten/graphics/matrix"
 	"image"
-	"image/color"
 	_ "image/png"
 	"math"
 	"os"
@@ -71,7 +70,7 @@ func (game *Rotating) Update(context ebiten.GameContext) {
 }
 
 func (game *Rotating) Draw(g graphics.Context) {
-	g.Fill(&color.RGBA{R: 128, G: 128, B: 255, A: 255})
+	g.Fill(128, 128, 255)
 	g.DrawTexture(game.ebitenTexture.ID(),
 		game.geometryMatrix,
 		matrix.IdentityColor())
diff --git a/example/game/sprites/sprites.go b/example/game/sprites/sprites.go
index e1d0a8a60..28ede3c0c 100644
--- a/example/game/sprites/sprites.go
+++ b/example/game/sprites/sprites.go
@@ -25,7 +25,6 @@ import (
 	"github.com/hajimehoshi/go.ebiten/graphics"
 	"github.com/hajimehoshi/go.ebiten/graphics/matrix"
 	"image"
-	"image/color"
 	"math/rand"
 	"os"
 	"time"
@@ -123,7 +122,7 @@ func (game *Sprites) Update(context ebiten.GameContext) {
 }
 
 func (game *Sprites) Draw(g graphics.Context) {
-	g.Fill(&color.RGBA{R: 128, G: 128, B: 255, A: 255})
+	g.Fill(128, 128, 255)
 
 	// Draw the sprites
 	locations := make([]graphics.TexturePart, 0, len(game.sprites))
diff --git a/graphics/graphics.go b/graphics/graphics.go
index d2c9e90d3..b3eabe625 100644
--- a/graphics/graphics.go
+++ b/graphics/graphics.go
@@ -23,7 +23,6 @@ package graphics
 import (
 	"github.com/hajimehoshi/go.ebiten/graphics/matrix"
 	"image"
-	"image/color"
 )
 
 type Rect struct {
@@ -42,7 +41,7 @@ type TexturePart struct {
 type Context interface {
 	Screen() RenderTarget
 	Clear()
-	Fill(clr color.Color)
+	Fill(r, g, b uint8)
 	DrawTexture(textureID TextureID,
 		geometryMatrix matrix.Geometry,
 		colorMatrix matrix.Color)
diff --git a/graphics/opengl/context.go b/graphics/opengl/context.go
index de556f51c..4ced8f94a 100644
--- a/graphics/opengl/context.go
+++ b/graphics/opengl/context.go
@@ -30,7 +30,6 @@ import (
 	"github.com/hajimehoshi/go.ebiten/graphics"
 	"github.com/hajimehoshi/go.ebiten/graphics/matrix"
 	"image"
-	"image/color"
 	"math"
 	"unsafe"
 )
@@ -77,18 +76,16 @@ func (context *Context) Screen() graphics.RenderTarget {
 }
 
 func (context *Context) Clear() {
-	C.glClearColor(0, 0, 0, 255)
-	C.glClear(C.GL_COLOR_BUFFER_BIT)
+	context.Fill(0, 0, 0)
 }
 
-func (context *Context) Fill(clr color.Color) {
-	r, g, b, a := clr.RGBA()
-	const max = float64(math.MaxUint16)
+func (context *Context) Fill(r, g, b uint8) {
+	const max = float64(math.MaxUint8)
 	C.glClearColor(
 		C.GLclampf(float64(r)/max),
 		C.GLclampf(float64(g)/max),
 		C.GLclampf(float64(b)/max),
-		C.GLclampf(float64(a)/max))
+		1)
 	C.glClear(C.GL_COLOR_BUFFER_BIT)
 }