rgba(255, 0, 0, 1.0)
rgba(255, 0, 0, 0.8)
rgba(255, 0, 0, 0.6)
rgba(255, 0, 0, 0.4)
rgba(255, 0, 0, 0.2)
opacity:1.0
opacity:0.8
opacity:0.6
opacity:0.4
opacity:0.2