Question about the Small Palette challenge. Say I have an image that is a PNG with only black and white - ensured via GIMP's Posterize feature. Then I save it as a JPG to save some file size. This may (will) introduce artifacts in the image, which will be many shades from black to white. Busted?
So, do we need to restrict ourselves to non-artifacting / non-lossy image formats if we want to qualify for Small Palette?