I inserted a color card and changed the color of the background I’m drawing on from white to grey, so when I render it, it comes out white and all my lines show. That’s good, but I want the final/rendered version to come out with the grey background instead of white. Is it possible to do that?
Right-click on the Colour-Card layer in the Timeline View and choose Layer Properties.
The Layer Properties box will open with a color bar under the field labeled “Alpha” (white is the default color)
Click on that bar and a box will open with color wheels to change the color of your Colour-Card.
There is an eyedropper so you can select the identical color of any existing object including your drawing background color.