Can now save and load from json

Much improved speed over loading everything manually.

colors.go

@@ -0,0 +1,57 @@
+package ps
+
+import (
+	"encoding/hex"
+)
+
+var Colors map[string]Color = map[string]Color{
+	"Gray":  &RGB{128, 128, 128},
+	"White": &RGB{255, 255, 255},
+}
+
+// Color represents a color.
+type Color interface {
+	RGB() [3]int
+}
+
+func Compare(a, b Color) Color {
+	A := a.RGB()
+	B := b.RGB()
+	Aavg := (A[0] + A[1] + A[2]) / 3
+	Bavg := (B[0] + B[1] + B[2]) / 3
+	if Aavg > Bavg {
+		return a
+	}
+	return b
+}
+
+// Color is a color in RGB format.
+type RGB struct {
+	Red   int
+	Green int
+	Blue  int
+}
+
+// RGB returns the color in RGB format.
+func (r RGB) RGB() [3]int {
+	return [3]int{r.Red, r.Green, r.Blue}
+}
+
+// Hex is a color in hexidecimal format.
+type Hex []uint8
+
+func (h Hex) RGB() [3]int {
+	src := []byte(h)
+	dst := make([]byte, hex.DecodedLen(len(src)))
+	_, err := hex.Decode(dst, src)
+	if err != nil {
+		panic(err)
+	}
+	return [3]int{int(dst[0]), int(dst[1]), int(dst[2])}
+}
+
+// Stroke represents a layer stroke effect.
+type Stroke struct {
+	Size float32
+	Color
+}