There are 3 editor skins to choose from for CKeditor, I changed the default from kama to v2 based on user feedback that the kama skin looked goofy. I kind of liked it myself but I'm mildly color blind and may not see it as others do. To me it looks like nice soft pastels, but others said it looks cartoony.
<!-- valid options for CKeditor:Skin are kama, v2, office2003-->
<add key="CKEditor:Skin" value="v2"/>
You can override it in user.config
Best,
Joe