Menu colors not showing properly

Created web page using webstyle 4, elements template. I am using the left navigation buttons. The only change I've made to the buttons is adding the navigation. I have not changed the colors. However, when I view my page and buttons in the browser (Internet Explorer) the mouse over colors of the submenus is not correct. It appears to be the same as the background color. When I check the colors in webstyle they have not been altered. But these default colors are not what is showing up when viewed in the browser. What can cause this and how can I correct this? This is for an intranet so I cannot share the path to the page.
Thanks so much for your help.