With Farbfeld, it's possible to further reduce the size of image data to be 24 bytes, or 16 if you're ok with your image not being displayable

    Magic Number: 66 61 72 62 66 65 6c 64 (identifies the file as a Farbfeld image)
    Width (in bytes): 00 00 00 01 (specifies the image width)
    Height (in bytes): 00 00 00 01 (specifies the image height)
    First Pixel Data: ff ff ff ff ff ff ff ff (represents the color data for the first pixel)