.DescartesToolBar .DescartesButtonContentTaskAddLayerItemInactive {
    background: url("img/add_layer_disabled.gif") no-repeat center;
    float:left;
}
.DescartesToolBar .DescartesButtonContentTaskAddLayerItemActive {
    background: url("img/add_layer_enabled.gif") no-repeat center;
    float:left;
}
.vakata-context .DescartesButtonContentTaskAddLayerContextMenu {
    background: url("img/add_layer_enabled.gif") no-repeat center;
}