Colorized barcode

To colorize a barcode you could use the following code:

package main

import (
    "github.com/boombuler/barcode"
    "github.com/boombuler/barcode/qr"
    "image/color"
    "image/png"
    "os"
)

type coloredBarcode struct {
    barcode.Barcode
    cm color.Model
    fg color.Color
    bg color.Color
}

func NewColoredBarcode(bc barcode.Barcode, cm color.Model, foreground color.Color, background color.Color) barcode.Barcode {
    return &coloredBarcode{bc, cm, foreground, background}
}
func (bc *coloredBarcode) ColorModel() color.Model {
    return bc.cm
}
func (bc *coloredBarcode) At(x, y int) color.Color {
    c := bc.Barcode.At(x, y)
    if c == color.Black {
        return bc.fg
    } else {
        return bc.bg
    }
}

func main() {
    bc, _ := qr.Encode("foobar", qr.L, qr.Auto)
    bc = NewColoredBarcode(bc, color.RGBAModel, color.RGBA{255, 0, 0, 255}, color.RGBA{255, 255, 0, 255})
    f, _ := os.Create("foobar.png")
    defer f.Close()
    png.Encode(f, bc)
}