Make reading pane transparent

First, my compliments on your coding. It resists hackers better than most themes I previewed during a bunch of recent hacks on the insecure Arvixe servers. Most showed an Islam flag waving and yours didn’t even though my site title was garbled. I am in the process of changing hosts and deleted Velocity, a paid theme I thought would do what Blogger did before I moved to WordPress: show my background picture through the posts. Not so. Instead, Velocity’s header hogged most of my page, post titles and page titles overlapped, and some titles were invisible against a dark background along with comments. Support never fixed those problems or I wouldn’t be here. I chose Tempera for all the features I thought Velocity had, including responsive layout. But I thought Tempera would let me make my post background translucent, and I can’t figure out how. I really want to see earth in space through the reading pane. Is there any chance of making that option available without making a child theme? I will be happy to donate $25 if I can do that. Seeing Fluida’s rain on glass header is what prompted me to ask. If it’s easier to adjust transparency via Fluida, I will switch when it’s ready for prime time. I don’t have enough knowledge to beta test.