span.sp-thumb-title {
    position: absolute;
    color: #fff;
    background: rgba(0, 0, 0, 0.6);
    padding: 5px 10px;
    font-weight: normal;
    font-family: 'PT Sans', sans-serif;
    line-height: 1.3;
} 

.slider-pro p.sp-layer a {
    color: #fff;
}