The default color for the background (canvas) is black and is therefore the color that will be used if no background asset is added.
This is how you change the color:
Click on the asset lane (under your slide) to open the group menu
Open color setting
Update the color on the object you want to update
The colors available are dependent on the Theme used. Learn more about what Primary, Darken, Text on Primary, Theme Color 1, etc means.
Tips!
If you would like to change the default canvas color for all your slides, just update your video theme.
You can also turn on "slide tint" and set it to 100% to set a color to the slide.
Adding a coloured background (Video tutorial)
What you'll learn
Working with slides with or without an asset
Adding theme or custom colours
Adjusting the tint overlay
Level up your Storykit skills with more video tutorials here.