I would like to request the ability to change the text color on the lock screen and the bottom of the Charms Bar "Settings" part where you have the Power, PC Settings, Network, etc. located. 

On the lock screen the only color for text is white, thereby making use of lighter colored backgrounds not usable as the text would be unreadable.

On the Charms Bar, click Settings and you'll see at the bottom the text for the items are in white. If one picks a light colored charms bar background (alternate color?) then the text would be impossible to read.

It would be nice to be able to customize these areas, especially the lock screen text.