Yes, you can customize the Gist messenger to match your brand, and we certainly recommend that you do so.
You can change the color of the button and the messenger widget in the settings tab. Note that the color of your conversations will also change. For example, if you chose the color black, your messenger will look like this:
You can preview the changes you make right there, and modify the settings if you want.
You can also customize the Gist Messenger by:
1. Choosing to enable or disable the chat entirely, and
2. Editing the default text that appears when users click on the messenger on your site.
We recommend you to urge users to give you their email address to encourage more conversions. The default text already does this, but you can make changes to the text to suit your tone and style.
If you need any assistance with setting up Gist messenger on your site, send us a message over chat.