Solid Black Background

1 I want to create a solid color "video" segment in my overall video. In iMovie I can add it by importing a background. I don't see any such feature in Premiere Pro. How do I add a black (or other color) solid color background to my timeline?

I have MP3 audio that I would like to turn into video, by joining the audio with a solid black background. I then want to upload the video to Youtube. Using ffmpeg, I have tried this command, and ...

solid black background 2

I have created multiple text layers (which is ok) but then I had to create multiple solids, one for each line of text to add the black background-colour: I am wondering if there is an easier way, maybe a built-in title effect that I don't know.

solid black background 3

When I view it (by pressing 2), the background turns solid black instead of showing the transparent checkerboard. How can I properly import or fix a PNG in Fusion so the transparent background stays transparent?

solid black background 4

but it replaces the green screen with solid black, whereas I would like it replaced with a transparent background, alpha = 0. I tried setting the color to #00000000 (8 zeroes indicating a zero alpha), but that still resulted in a black background. Strangely, when I set the color to say red, it gives a red tint to many unfiltered areas.

solid black background 5

I am trying to set my desktop background to a neutral grey but every time I do this the icon font changes to a hideous "hollow white" and I cannot find how to change it to a solid black. It seems that the background/font are linked and fixed. Help?