In the Branding section you can:
add your company’s logo;
adjust logo size (small/medium/large);
upload dashboard image;
toggle project name visibility;
Note: This option is available only if the logo is applied. You may find it useful in case your logo already contains the project name, or you'd like to spare some space on the top bar.
adjust user interface color;
customize login page background.
Minimum resolution of the login page background: 1280x1024px.
Picture adapts to any screen size, fills the entire area, so no empty blocks are left and is automatically optimized for high loading speed.
Supported formats of logo, dashboard image & login page background:
JPEG | JPG | PNG.
Check out this article about the difference between logo, dashboard image and login page background.