Hi Zhang, can you be more specific i.e. what is it that we shall be looking for/at? From what I can see, everything looks fine as is.
Hmm .... well, maybe to much colors i.e. I think it would be easier if the Admin panel would mabe have just white background and mabye two colors for all other things.
Two different flavors blue and gray makes for 4 different colors in total; imo that slices the overall panel in too many fields so it becomes harder to quickly get an overview as you "move" trough different menues.
In short: try to save folks as much time as possible by creating a trivial color theme -- the easier it is, the more effective folks are when using the admin panel ...