The grey bullet list style is an image that the theme has css for. How did you add your own to show up on the lists, and is this the style you want for your default style of list? The styling for the lists are in the style.css file and begin around line 650. The default one (loads a grey bullet image) looks like this:
ul li {
padding-left: 16px;
background: transparent url('images/sprite-list.png') -212px 0 no-repeat;
}