PNG file don't show properly. (wrong order in index?)

[riffnshred]

I've found a bug when I upload a PNG file. The image load as the right size but the index of color seems to be all over the place.

I tested both PNG and BMP and the BMP file works great.

# SPDX-FileCopyrightText: 2020 Jeff Epler for Adafruit Industries
#
# SPDX-License-Identifier: MIT

# This example implements a simple two line scroller using
# Adafruit_CircuitPython_Display_Text. Each line has its own color
# and it is possible to modify the example to use other fonts and non-standard
# characters.

import adafruit_display_text.label
import board
import time
import ulab
import displayio
import framebufferio
import rgbmatrix
import terminalio
import adafruit_imageload

displayio.release_displays()

matrix = rgbmatrix.RGBMatrix(
    width=64, height=32, bit_depth=3,
    rgb_pins=[
        board.MTX_R1,
        board.MTX_G1,
        board.MTX_B1,
        board.MTX_R2,
        board.MTX_G2,
        board.MTX_B2
    ],
    addr_pins=[
        board.MTX_ADDRA,
        board.MTX_ADDRB,
        board.MTX_ADDRC,
        board.MTX_ADDRD
    ],
    clock_pin=board.MTX_CLK,
    latch_pin=board.MTX_LAT,
    output_enable_pin=board.MTX_OE,
)

display = framebufferio.FramebufferDisplay(matrix)

# load png image
image, palette = adafruit_imageload.load("ANA.png")

print(f"Logo is {image.width}x{image.height}")

# make tilegrid for the loaded image
tile_grid = displayio.TileGrid(image, pixel_shader=palette)

print(f"TileGrid is {image.width}x{image.height}")

# Put each line of text into a Group, then show that group.
g = displayio.Group()

# add loaded image tilegrid
g.append(tile_grid)
display.show(g)

# You can add more effects in this loop. For instance, maybe you want to set the
# color of each label to a different value.
while True:
    display.refresh(minimum_frames_per_second=0)

PNG version

BMP version

[deshipu]

I think this is the result of adafruit/circuitpython#6675