Is this a worpress bug?

After my learning about css on my previous post, I found that the page will load a little bit longer compare when I use my default theme, I don’t know is it because I delete the image section on header.php, bacause I thougt it will load faster if I remove image from my web. I just change in style.css the background-color of header, page, and footer to green (#73a010).

It took more than 2 second to load my web, before it only take 0.7 second, I know I can’t blame the them, maybe its about th connection that sux!.