I believe the buttons blend in too well with the background. Their hard to separate visually.
Looking at it again, I tend to agree. I will try and darken them up a little... thanks for this observation.
I wouldn't darken the buttons, but maybe change the container they are in.
As far as looks go I have to say TinyMCE had it covered pretty well. Anyone else who tends to agree on that or is it just me?