Colors and typography. In the editor toolbar open Configuration → Course Studio → Theming to choose a colour theme (with a live preview), and Typography / Motion for fonts and animation.
Header logo and background.
Open Configuration → Learner Experience → Header & Background to upload your logo and set the header background and colour.
Course background. In the same Header & Background area, set a course background image or video and apply effects.
Title screen.
Select Title Screen in the Introduction group of the structure tree. Set the course title, logo, background image and a preset Layout (Portrait Image, Left/Center Banner, Half Filter, Center Image, Symmetrical Split/Slice, Default), with a live preview. Brand this screen so learners recognise it as an official source.
You can also Upgrade to Flex for a fully custom title screen.