diff --git a/example/blocks/blocks/gamescene.go b/example/blocks/blocks/gamescene.go
index 20fb5c8fd..782a2cb08 100644
--- a/example/blocks/blocks/gamescene.go
+++ b/example/blocks/blocks/gamescene.go
@@ -110,7 +110,7 @@ func (s *GameScene) Update(state *GameState) {
 }
 
 func (s *GameScene) Draw(context ebiten.GraphicsContext, textures *Textures) {
-	context.Fill(0xff, 0xff, 0xff)
+	context.Fill(color.White)
 
 	field := textures.GetTexture("empty")
 	w, h := field.Size()
diff --git a/example/paint/main.go b/example/paint/main.go
index eaf7030a8..8c03adb11 100644
--- a/example/paint/main.go
+++ b/example/paint/main.go
@@ -43,10 +43,10 @@ func (g *Game) Update(gr ebiten.GraphicsContext) error {
 	}
 	if !g.inited {
 		gr.PushRenderTarget(g.brushRenderTarget)
-		gr.Fill(0xff, 0xff, 0xff)
+		gr.Fill(color.White)
 		gr.PopRenderTarget()
 		gr.PushRenderTarget(g.canvasRenderTarget)
-		gr.Fill(0xff, 0xff, 0xff)
+		gr.Fill(color.White)
 		gr.PopRenderTarget()
 		g.inited = true
 	}
diff --git a/example/perspective2/main.go b/example/perspective2/main.go
deleted file mode 100644
index 310e1ca4b..000000000
--- a/example/perspective2/main.go
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
-Copyright 2014 Hajime Hoshi
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package main
-
-import (
-	"github.com/hajimehoshi/ebiten"
-	"github.com/hajimehoshi/ebiten/ebitenutil"
-	_ "image/jpeg"
-	"log"
-)
-
-const (
-	screenWidth  = 320
-	screenHeight = 240
-)
-
-type Game struct {
-	gophersTexture   *ebiten.Texture
-	textRenderTarget *ebiten.RenderTarget
-}
-
-func (g *Game) Update(gr ebiten.GraphicsContext) error {
-	gr.PushRenderTarget(g.textRenderTarget)
-	gr.Fill(0x80, 0x40, 0x40)
-	ebitenutil.DebugPrint(gr, "Hello, World!")
-	gr.PopRenderTarget()
-
-	gr.Fill(0x40, 0x40, 0x80)
-	geo := ebiten.GeometryMatrixI()
-	clr := ebiten.ColorMatrixI()
-	ebiten.DrawWholeTexture(gr, g.textRenderTarget.Texture(), geo, clr)
-	return nil
-}
-
-func main() {
-	g := new(Game)
-	var err error
-	g.gophersTexture, _, err = ebitenutil.NewTextureFromFile("images/gophers.jpg", ebiten.FilterNearest)
-	if err != nil {
-		log.Fatal(err)
-	}
-	g.textRenderTarget, err = ebiten.NewRenderTarget(screenWidth, screenHeight, ebiten.FilterNearest)
-	if err != nil {
-		log.Fatal(err)
-	}
-	if err := ebiten.Run(g.Update, screenWidth, screenHeight, 2, "Perspective (Ebiten Demo)"); err != nil {
-		log.Fatal(err)
-	}
-}
diff --git a/graphics.go b/graphics.go
index 0856c4f6e..2a2156517 100644
--- a/graphics.go
+++ b/graphics.go
@@ -17,9 +17,8 @@ limitations under the License.
 package ebiten
 
 import (
-	"github.com/hajimehoshi/ebiten/internal"
 	"github.com/hajimehoshi/ebiten/internal/opengl"
-	"github.com/hajimehoshi/ebiten/internal/opengl/internal/shader"
+	"image/color"
 )
 
 // A Rect represents a rectangle.
@@ -48,7 +47,7 @@ func DrawWholeTexture(g GraphicsContext, texture *Texture, geo GeometryMatrix, c
 // A GraphicsContext is the interface that means a context of rendering.
 type GraphicsContext interface {
 	Clear() error
-	Fill(r, g, b uint8) error
+	Fill(clr color.Color) error
 	DrawTexture(texture *Texture, parts []TexturePart, geo GeometryMatrix, color ColorMatrix) error
 	// TODO: ScreenRenderTarget() Drawer
 	PushRenderTarget(id *RenderTarget)
@@ -91,28 +90,3 @@ func (r *RenderTarget) Texture() *Texture {
 func (r *RenderTarget) Size() (width int, height int) {
 	return r.glRenderTarget.Width(), r.glRenderTarget.Height()
 }
-
-func u(x float64, width int) float32 {
-	return float32(x) / float32(internal.AdjustSizeForTexture(width))
-}
-
-func v(y float64, height int) float32 {
-	return float32(y) / float32(internal.AdjustSizeForTexture(height))
-}
-
-func textureQuads(parts []TexturePart, width, height int) []shader.TextureQuad {
-	quads := make([]shader.TextureQuad, 0, len(parts))
-	for _, part := range parts {
-		x1 := float32(part.Dst.X)
-		x2 := float32(part.Dst.X + part.Dst.Width)
-		y1 := float32(part.Dst.Y)
-		y2 := float32(part.Dst.Y + part.Dst.Height)
-		u1 := u(part.Src.X, width)
-		u2 := u(part.Src.X+part.Src.Width, width)
-		v1 := v(part.Src.Y, height)
-		v2 := v(part.Src.Y+part.Src.Height, height)
-		quad := shader.TextureQuad{x1, x2, y1, y2, u1, u2, v1, v2}
-		quads = append(quads, quad)
-	}
-	return quads
-}
diff --git a/graphicscontext.go b/graphicscontext.go
index 60a855375..96578a923 100644
--- a/graphicscontext.go
+++ b/graphicscontext.go
@@ -19,6 +19,7 @@ package ebiten
 import (
 	"github.com/go-gl/gl"
 	"github.com/hajimehoshi/ebiten/internal/opengl"
+	"image/color"
 )
 
 func newGraphicsContext(screenWidth, screenHeight, screenScale int) (*graphicsContext, error) {
@@ -41,7 +42,7 @@ func newGraphicsContext(screenWidth, screenHeight, screenScale int) (*graphicsCo
 		screenScale:  screenScale,
 	}
 
-	idsInstance.fillRenderTarget(c.screen, 0, 0, 0)
+	idsInstance.fillRenderTarget(c.screen, color.RGBA{0, 0, 0, 0})
 
 	return c, nil
 }
@@ -68,11 +69,11 @@ func (c *graphicsContext) dispose() {
 }
 
 func (c *graphicsContext) Clear() error {
-	return c.Fill(0, 0, 0)
+	return c.Fill(color.RGBA{0, 0, 0, 0})
 }
 
-func (c *graphicsContext) Fill(r, g, b uint8) error {
-	return idsInstance.fillRenderTarget(c.currents[len(c.currents)-1], r, g, b)
+func (c *graphicsContext) Fill(clr color.Color) error {
+	return idsInstance.fillRenderTarget(c.currents[len(c.currents)-1], clr)
 }
 
 func (c *graphicsContext) DrawTexture(texture *Texture, parts []TexturePart, geo GeometryMatrix, color ColorMatrix) error {
diff --git a/ids.go b/ids.go
index 24b147708..fd582cd93 100644
--- a/ids.go
+++ b/ids.go
@@ -18,8 +18,10 @@ package ebiten
 
 import (
 	"github.com/go-gl/gl"
+	"github.com/hajimehoshi/ebiten/internal"
 	"github.com/hajimehoshi/ebiten/internal/opengl"
 	"github.com/hajimehoshi/ebiten/internal/opengl/internal/shader"
+	"image/color"
 	"math"
 )
 
@@ -45,17 +47,19 @@ func (i *ids) createRenderTarget(width, height int, filter int) (*RenderTarget,
 	}
 
 	texture := &Texture{glTexture}
+	// TODO: Is |texture| necessary?
 	renderTarget := &RenderTarget{glRenderTarget, texture}
 
 	return renderTarget, nil
 }
 
-func (i *ids) fillRenderTarget(renderTarget *RenderTarget, r, g, b uint8) error {
+func (i *ids) fillRenderTarget(renderTarget *RenderTarget, clr color.Color) error {
 	if err := i.setViewportIfNeeded(renderTarget); err != nil {
 		return err
 	}
-	const max = float64(math.MaxUint8)
-	gl.ClearColor(gl.GLclampf(float64(r)/max), gl.GLclampf(float64(g)/max), gl.GLclampf(float64(b)/max), 1)
+	const max = math.MaxUint16
+	r, g, b, a := clr.RGBA()
+	gl.ClearColor(gl.GLclampf(float64(r)/max), gl.GLclampf(float64(g)/max), gl.GLclampf(float64(b)/max), gl.GLclampf(float64(a)/max))
 	gl.Clear(gl.COLOR_BUFFER_BIT)
 	return nil
 }
@@ -82,3 +86,28 @@ func (i *ids) setViewportIfNeeded(renderTarget *RenderTarget) error {
 	}
 	return nil
 }
+
+func u(x float64, width int) float32 {
+	return float32(x) / float32(internal.AdjustSizeForTexture(width))
+}
+
+func v(y float64, height int) float32 {
+	return float32(y) / float32(internal.AdjustSizeForTexture(height))
+}
+
+func textureQuads(parts []TexturePart, width, height int) []shader.TextureQuad {
+	quads := make([]shader.TextureQuad, 0, len(parts))
+	for _, part := range parts {
+		x1 := float32(part.Dst.X)
+		x2 := float32(part.Dst.X + part.Dst.Width)
+		y1 := float32(part.Dst.Y)
+		y2 := float32(part.Dst.Y + part.Dst.Height)
+		u1 := u(part.Src.X, width)
+		u2 := u(part.Src.X+part.Src.Width, width)
+		v1 := v(part.Src.Y, height)
+		v2 := v(part.Src.Y+part.Src.Height, height)
+		quad := shader.TextureQuad{x1, x2, y1, y2, u1, u2, v1, v2}
+		quads = append(quads, quad)
+	}
+	return quads
+}
diff --git a/syncgraphicscontext.go b/syncgraphicscontext.go
index 022f8d1f5..daa63e78a 100644
--- a/syncgraphicscontext.go
+++ b/syncgraphicscontext.go
@@ -16,6 +16,10 @@ limitations under the License.
 
 package ebiten
 
+import (
+	"image/color"
+)
+
 type syncer interface {
 	Sync(f func())
 }
@@ -34,9 +38,9 @@ func (c *syncGraphicsContext) Clear() (err error) {
 	return
 }
 
-func (c *syncGraphicsContext) Fill(r, g, b uint8) (err error) {
+func (c *syncGraphicsContext) Fill(clr color.Color) (err error) {
 	c.syncer.Sync(func() {
-		err = c.innerGraphicsContext.Fill(r, g, b)
+		err = c.innerGraphicsContext.Fill(clr)
 	})
 	return
 }