How to change the padding color of frames
If you have added a custom format with padding or chosen a format like the 'Square Letterbox', you might want to change the letterbox padding color. This can be easily achieved with just a few clicks. This can be very helpful in brand building.
To change the color of the padding, follow the steps below.
Step 1: Click 'Settings
' on the top left of your editing canvas.
Step 2: This opens up the Project Settings. Navigate to Project defaults > Padding color. Click the + icon to choose and choose a color that compliments your video and the brand. 
Step 3: The new color you have chosen will now reflect on the timeline.
Note - You can also change the format of your video from the 'Project Settings'.
Related Articles: How to View your Project Settings How to Resize your video