Your logo and main color are displayed on every member-facing web page, as well as the member portal app. So it is important your logo looks good and you have a main color theme that is consistent across the system.
To set this, go to your Settings. Then:
1. Upload a square version of your logo. This is important. If a rectangle logo is uploaded, it will be squeezed to fit a square image.
image size: 500x500p @ 72DPI
2. Under 'Misc Settings', set your main color. Click on the default color. This will open up a selector where you can select from pre-defined color themes.