You can change the colors of the offer [background, button] and modify the title and description. Below is how you do it.
1. Click on Create Campaign on the Left Navigation bar
2a. Click on the "Modify Message" link under the SEND button
2b. Click on the "Modify Message" link under the SEND button
3. Customize your offer and details
4. Click [SEND] or [BACK] and [SEND]