custom_nodes/ComfyUI-VideoHelperSuite/video_formats/ffmpeg-gif.json

{
    "main_pass":
    [
        "-n",
        "-filter_complex", ["dither", ["bayer", "heckbert", "floyd_steinberg", "sierra2", "sierra2_4a", "sierra3", "burkes", "atkinson", "none"], {"default": "sierra2_4a"}, "[0:v] split [a][b]; [a] palettegen=reserve_transparent=on:transparency_color=ffffff [p]; [b][p] paletteuse=dither=$val"]
    ],
    "extension": "gif"
}