I went to Pep Boys today to get an Optima Yellow top. They do not sell Yellow tops. They have Red and Blue (marine). I went to the Optima web site and could not find much difference in the Yellow vs. Blue except the blue did not have side posts, which I do not need anyway and it had two little accessory posts on top. So, my question is this, Do any of you know of a significant difference between the Yellow top and the Blue top? Oh yeah, the Blue top was 149.95 at Pep Boys. That's because I'm the devil.