Need to have multiple overlapping HTML Overlays

I have animations in separate .html files and each one uses webvfx inside to sychronize to the video properly - I want to keep each one independent…I do not want to create a single .html containing the multiple different animations.

I have a track of video (V1) and use one of the .html files as an overlay directly on it, and it works fine.

Now I want to apply one of the other .html animations on top, or even to appear for a subset of time in the timeline.

So I add a new track (V2).

I tried using “Open Other” and adding a “black” dummy track #0000000 …but it seems the HTML Overlay will not show on transparent data…the 2nd HTML Overlay doesn’t work. If I choose a colour with some opacity, then it doesn’t show the HTML Overlay but WITH the colour too, which is not what I want.

Not possible to use chroma key, as I wouldn’t be able to choose a colour guaranteed to not be used within the HTML overlay.

I suggest there should be an option on the HTML Overlay filter which will blend the HTML Overlay even on transparent “bases”.

Or maybe there is another way to do it ? thanks.

Are your HTML Overlays displaying some kind of rainbow mandelbrot thing? If you can find just one color that won’t appear, ChromaKey will work with multiple overlays (I just tested it).

If your overlay involves gradients or anti-aliased text, or other graphics, etc, then using a color key is not possible, as you will get holes in your content…the artifacts would be noticeable on a tv.