I don't have a subscription to the phpBB club, so cannot post to the relevant forums. I was considering buying the crystaline template, but I've noticed there appears to be a bug.
If I set the body colour to black in the colour chooser, the text in the selection boxes becomes invisible. There doesn't appear to be any way to control what colour it uses, and consequently the black text on a black background renders it invisible.
I don't seem to have any means of uploading a screenshot, so I hope the description is useful. The page I was using for testing was
demo.rockettheme.com/phpbb3/viewforum.php?style=62&ntheme=&f=5
and I'm looking at the page on Safari. I set the body>background colour (in the colour chooser) to #000000 and all selection boxes become hard to see (i.e. "Display topics from previous:").