There is no evidence to suggest that Latisse will change your eye color. Over two and a half million prescriptions for Latisse have been filled with no confirmed reports of iris pigmentation changes. So there is no possibility of Latisse entering your blood stream and affecting your eye color....
The medication in Latisse that is sold in the United States is bimatoprost ophthalmic solution 0.03%. To my knowledge, all of the studies that prove its effectiveness for growing eyelashes were done using the 0.03% solution so I would recommend not take any chances by using a lower...
Latisse should have an expiration on the box as it is an FDA approved medication. It lasts a long time, but check the expiration date on the box to be sure. And, be careful not to store it under extreme conditions (like heat).