From Admin Panel > Platform > Customize appearance you can configure this aspects:
1. Plataform Logo
Allows you to choose your organization´s logo, to display at the login page and header. Transparent background png images are recommended.
2. Platform Color
Choose the color of the top header.
3. Text contrast
Here you can choose the color of the text that best contrasts with the color chosen earlier.
4. Background image
Allows you to choose an image for the background of the login screen. 683 x 768 px jpg images are recommended.
Return to default settings
If you want to return to the default settings, at the end of the Image settings you have the option.
Once you're done, remember to Save all changes.