WordPress 2.5 already provide two types of color schemes for dashboard. They are “Classic” and “Fresh“. By default, you will have the “Fresh” color scheme. It’s light shades of blue. If you like the darker blue, you can switch to it by choosing the “Classic” style. If you haven’t touch this area, this setting can be found on your profile page. Just click your name on the top right navigation.

In WordPress 2.7, we can do the same. The color schemes available to choose are “Blue” and “Gray” (default).

Right now, I choose the “Blue” scheme. Look at these picture for color scheme comparison.
Using plugins, we can have different color scheme and additional elements inside dashboard. This is my dashboard color scheme when I used WordPress 2.6.5.

I like my current dashboard — the “Blue” scheme. I think I’ll modify/create my color scheme later… just for fun! :)