Is there any way to lighten these up?
No there isn't, unfortunately.
I do have a sort-of solution to this though, but it involves darkening everything else! On my laptop the whole of Audition looks too bright (and I'm not alone in thinking this either, I happen to know), so I run it with the UI 'brightness' slider set to 19 instead of the default 50. When you do this, the iZotope compressors look about the same as the rest of the UI. That would work for you too, but you would have to turn up the brightness on your monitor to get a balanced effect. Does work quite well, though...