In Design Editor I can do most of what I need, but it automatically puts a turquoise play icon over my Vimeo video GIF which doesn't match my branding. I usually add my own play icon over my animated GIF. I know I can make the turquoise part transparent, but the white triangle doesn't show up over a mostly white background. I also can't make the white triangle transparent to show my play icon. Trying to overlay them works for one device viewer but loses alignment when viewing in a different one.

If I could access the HTML I could fix that.