Doctor M said:
Don't do any of the black and white thing.
James O'barr wrote the comic, not the script. He did not direct it. There's a reason he isn't responsible for any artistic choices; he is not a filmmaker.
If Alex Proyas had wanted black and white, he is artistically creative enough to have done it.
Leave the color.
I'd rather you found away to restore the Skull Cowboy.
Turns out Alex wanted it also
Director Alex Proyas originally wanted to shoot the entire movie in "black and white" closer to the comics and only using color in Draven's flash backs scenes with high contrast theme, but the studio executives didn't allow him to experiment with approach. This made Proyas shoot much of the movie in a monochromatic color theme mixed with red and dark gray.