Just a side note on the spots...
Use GIF compression and not JPG. PNG is not compatiable with some browsers, although it's been around long enough it should be...
JPG is a lossey format, and that's why you get spots. GIF is not lossey because it uses LZW compression. However, you can only have 256 colors in a GIF. Since the graphic will only have about 4 colors or so (white, black, orange, light grey) you are best off saving it as a GIF. JPG should be used for real world photographs and the like.
Cheers