#SNG: from basn3p08-trns.png
IHDR {
    width: 32; height: 32; bitdepth: 8;
    using color palette;
}
gAMA {1.0000}
PLTE {
    (255,  3,  7)     # rgb = (0xff,0x03,0x07)
    (255,  4,  7)     # rgb = (0xff,0x04,0x07)
    (255,  9,  7)     # rgb = (0xff,0x09,0x07)
    (217, 14,  7)     # rgb = (0xd9,0x0e,0x07)
    (255, 14,  7)     # rgb = (0xff,0x0e,0x07)
    (  2, 22, 19)     # rgb = (0x02,0x16,0x13)
    (255, 26,  7)     # rgb = (0xff,0x1a,0x07)

			b = append(b, trns...)
		}
		b = append(b, idat...)
		b = append(b, iend...)

		var want color.Color
		m, err := Decode(bytes.NewReader(b))
		switch i {
		case 0:
			if err != nil {
				t.Errorf("%d tRNS chunks: %v", i, err)
				continue
			}
			want = color.RGBA{0xff, 0x00, 0x00, 0xff}
		case 1:
			if err != nil {
				t.Errorf("%d tRNS chunks: %v", i, err)
				continue

	case cbTC8, cbTC16:
		if length != 6 {
			return FormatError("bad tRNS length")
		}
		n, err := io.ReadFull(d.r, d.tmp[:length])
		if err != nil {
			return err
		}
		d.crc.Write(d.tmp[:n])

		copy(d.transparent[:], d.tmp[:length])
		d.useTransparent = true

	case cbP1, cbP2, cbP4, cbP8:
		if length > 256 {
			return FormatError("bad tRNS length")
		}
		n, err := io.ReadFull(d.r, d.tmp[:length])

    ( 45, 45, 84)     # rgb = (0x2d,0x2d,0x54)
    ( 10, 10, 96)     # rgb = (0x0a,0x0a,0x60)
    (  0,  0,255)     # rgb = (0x00,0x00,0xff) blue1
    (191,125,125)     # rgb = (0xbf,0x7d,0x7d)
}
tRNS {
 0}
IMAGE {
    pixels hex
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000

#SNG: from ftbgn2c16.png
IHDR {
    width: 32; height: 32; bitdepth: 16;
    using color;
}
gAMA {1.0000}
bKGD {red: 0;  green: 65535;  blue: 0;}
tRNS {
    red: 65535; green: 65535; blue: 65535;
}
IMAGE {
    pixels hex

#SNG: from ftbbn2c16.png
IHDR {
    width: 32; height: 32; bitdepth: 16;
    using color;
}
gAMA {1.0000}
bKGD {red: 0;  green: 0;  blue: 65535;}
tRNS {
    red: 65535; green: 65535; blue: 65535;
}
IMAGE {
    pixels hex

    ( 45, 45, 84)     # rgb = (0x2d,0x2d,0x54)
    ( 10, 10, 96)     # rgb = (0x0a,0x0a,0x60)
    (  0,  0,255)     # rgb = (0x00,0x00,0xff) blue1
    (191,125,125)     # rgb = (0xbf,0x7d,0x7d)
}
bKGD {index: 0}
tRNS {
 0}
IMAGE {
    pixels hex
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000

    (  0,  0,255)     # rgb = (0x00,0x00,0xff) blue1
    (191,125,125)     # rgb = (0xbf,0x7d,0x7d)
    (  0,  0,  0)     # rgb = (0x00,0x00,0x00) grey0
}
bKGD {index: 245}
tRNS {
 0}
IMAGE {
    pixels hex
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000

    ( 10, 10, 96)     # rgb = (0x0a,0x0a,0x60)
    (  0,  0,255)     # rgb = (0x00,0x00,0xff) blue1
    (191,125,125)     # rgb = (0xbf,0x7d,0x7d)
    (170,170,170)     # rgb = (0xaa,0xaa,0xaa)
}
bKGD {index: 245}
tRNS {
 0}
IMAGE {
    pixels hex
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000

    (  0,  0,255)     # rgb = (0x00,0x00,0xff) blue1
    (191,125,125)     # rgb = (0xbf,0x7d,0x7d)
    (255,255,  0)     # rgb = (0xff,0xff,0x00) yellow1
}
bKGD {index: 245}
tRNS {
 0}
IMAGE {
    pixels hex
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000