typing test on a blue navigation bar

I am using frontpage 2000 and I crate a navigation bar with blue color. I have a white background. When I type a text on the bar. and I load it on a browser the text come out just fine. but it will have a gray square surrounding the bar. It only happen when I type the texts. When there is only the bar, the gray color square surround the bar will not be there. I tried to transparent the picture already. What can I do about it.