Several days ago, I experimented 2 colors to experiment on clustering pixel. This time I will try with 4 colors. This will add more detail into the art. I did this experiment in 200 minutes. Also, I was using GraphicsGale while the previous one I used GIMP.
For the start, I had a trouble on how to pick up the palette for the 4 colors. After looking at many references, I managed to pick my own colors. After that, I modified the art from the 2 colors.