JavaScript Challenge Play--Random Color

(The English Version of   JavaScript挑战赛--随机颜色)

Title: Write a function to return a string that can represents a color.

Requirements: 1. The color is random. The color string can be similar to "cf9c63", also similar to "rgb (211,100, 180)".

2. Code should be concise, clear, easy to read, good performance, and better than my solution.

And go to  http://blog.csdn.net/FuDesign2008/archive/2010/06/04/5646681.aspx  to see more! 

Good Luck !