Jason Riendorp, the Marketing Director for the Zune, has reported additional colors will be released including baby pink. This color is available for pre-order and is expected to release May 1. The additional colors have not been announced, but orange is a likely candidate due to the fact that pink and orange Zunes were gifted to the Zune team members.
After offering 3 colors (Black, White and Brown) The Zune Team will introduce a third and fourth color. The "new" Zunes will be a Baby Pink Zune coming next month (different from the limited edition Hot-Pink Zune's) and an upcoming Watermelon-Red Zune for the summer.
Zune also has 3 limited edition versions. Those Zunes were made in pink, orange, and red.
The Zune will launch a massive campaign next month and has hinted in releasing Zune 2.0 before the year ends.
UPDATE: ZuneScene apparently does not have a Pink Zune on hand...Read all about it here.