[#81628936] Use green knockout styles for the adhoc card delete overlay

Before:

![image](https://cloud.githubusercontent.com/assets/5796310/4835728/80616d60-5fba-11e4-85e9-86d7ce3badb8.png)

After:

![image](https://cloud.githubusercontent.com/assets/5796310/4835722/6f53deae-5fba-11e4-988d-c8da4b16ff39.png)

— David Trejo