fix: support rgb colors

closes #9

pkg/color/color.go

@@ -1,15 +1,31 @@
 package color
 
 import (
+	"fmt"
+	"image/color"
+
 	"github.com/hinshun/vt10x"
 )
 
 //go:generate go run colorsgen.go
 
 func GetColor(c vt10x.Color) string {
-	if c >= 1<<24 {
+	switch {
+	case c >= 1<<24:
 		return colors[int(vt10x.LightGrey)]
+	case c >= 1<<8:
+		rgb := intToRGB(int(c))
+		return fmt.Sprintf("#%02x%02x%02x", rgb.R, rgb.B, rgb.G)
+	default:
+		return colors[int(c)]
 	}
+}
 
-	return colors[int(c)]
+func intToRGB(c int) color.RGBA {
+	return color.RGBA{
+		R: uint8(c >> 16),
+		G: uint8(c >> 8),
+		B: uint8(c),
+		A: 255,
+	}
 }