Yes and no.
Get too many carrots, you can turn orange. ;)
But realistically, a glass of blended fruit isn't quite the same, and a serving is very small. You really, really have to overdose, and honestly, when was the last time you heard of someone landing in the ER for too much broccoli?
One smoothie for breakfast combined with regular meals and snacks isn't going to put you in any risk. Enjoy your yummies, just make sure you're accurately counting your calories. SMoothies generally have more than just veggies and fruit in them, so they can be calorie bombs if you're not careful!
Fruits are the things to watch out for; while they ARE healthy, they can be calorie-dense depending on the fruit, so you can overeat on them if you're not careful. www.sciencedaily.com/releases/2012/07/1207