lnwire: use color.RGBA instead of custom type in NodeAnnouncment

lnwire/lnwire.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
+	"image/color"
 	"io"
 	"math"
 
@@ -355,8 +356,8 @@ func writeElement(w io.Writer, element interface{}) error {
 				return err
 			}
 		}
-	case RGB:
+	case color.RGBA:
-		if err := writeElements(w, e.red, e.green, e.blue); err != nil {
+		if err := writeElements(w, e.R, e.G, e.B); err != nil {
 			return err
 		}
 
@@ -689,11 +690,11 @@ func readElement(r io.Reader, element interface{}) error {
 		}
 
 		*e = addresses
-	case *RGB:
+	case *color.RGBA:
 		err := readElements(r,
-			&e.red,
+			&e.R,
-			&e.green,
+			&e.G,
-			&e.blue,
+			&e.B,
 		)
 		if err != nil {
 			return err

lnwire/lnwire_test.go

@@ -3,6 +3,7 @@ package lnwire
 import (
 	"bytes"
 	"encoding/hex"
+	"image/color"
 	"math"
 	"math/big"
 	"math/rand"
@@ -404,10 +405,10 @@ func TestLightningWireProtocol(t *testing.T) {
 				Features:  randRawFeatureVector(r),
 				Timestamp: uint32(r.Int31()),
 				Alias:     a,
-				RGBColor: RGB{
+				RGBColor: color.RGBA{
-					red:   uint8(r.Int31()),
+					R: uint8(r.Int31()),
-					green: uint8(r.Int31()),
+					G: uint8(r.Int31()),
-					blue:  uint8(r.Int31()),
+					B: uint8(r.Int31()),
 				},
 				// TODO(roasbeef): proper gen rand addrs
 				Addresses: testAddrs,

lnwire/node_announcement.go

@@ -3,6 +3,7 @@ package lnwire
 import (
 	"bytes"
 	"fmt"
+	"image/color"
 	"io"
 	"net"
 	"unicode/utf8"
@@ -15,14 +16,6 @@ var (
 	endPort   uint16 = 49151
 )
 
-// RGB is used to represent the "color" of a particular node encoded as a 24
-// bit value.
-type RGB struct {
-	red   uint8
-	green uint8
-	blue  uint8
-}
-
 // NodeAlias a hex encoded UTF-8 string that may be displayed as an alternative
 // to the node's ID. Notice that aliases are not unique and may be freely
 // chosen by the node operators.
@@ -69,7 +62,7 @@ type NodeAnnouncement struct {
 
 	// RGBColor is used to customize their node's appearance in maps and
 	// graphs
-	RGBColor RGB
+	RGBColor color.RGBA
 
 	// Alias is used to customize their node's appearance in maps and
 	// graphs