Change Opacity of Background Image

Hi there!

I just updated Gommero and WordPress to the latest versions and I can no longer set the opacity of the background color. The website I’m working on is https://www.celebconn.com. This is what I had (and still have) in my Custom CSS:

body {
font: 14px/1.5 ‘Trebuchet MS’, sans-serif;
background:rgba(200,127,78,0.8) url(‘images/541.jpg’);
color:#000000;
background-attachment:fixed;
}

It appears that after the updates, I can set the background color in the Custom Background area, but how can I adjust the opacity without creating a gif image? Thanks!