Opacity change for header text in Full Width Easy Slider

Hi Guys,

I was trying to change the opacity of the header text in the fullwidth easy slider. I tried the following in the quick styles css, but no joy, could you tell me where I am going wrong?. I read that pacity is not supported by all browsers, is that right?.

Many thanks guys

Gary

.avia-caption-content h1 {

opacity: 0.5;}