Design fixes to the color picker:

* Apply top: 0 to .wp-color-result (open and closed).
* Reduce text size in hex-value field.
* Move hex-value-field styles to color-picker.css.

Fixes #26289, props mattheu.


Built from https://develop.svn.wordpress.org/trunk@26435


git-svn-id: http://core.svn.wordpress.org/trunk@26333 1a063a9b-81f0-0310-95a4-ce76da25c4cd