I’m new to forums, and have to say it’s so lovely to see people helping each other in a dialogue to help solve problems.
I received a reply from the maker of the product: Christmas Sparkler in Slow Motion.
Unfortunately I do not know anything about iMovie, But all editing programs work the same way.
You need to use Screen or Add blending mode or Luma Key for blending this footage over any image or video. And using Tint, Curve for change color.
If you can not mix a video using blending modes then I will prepare for you a video with alpha channel. But this video is going to be very havy for editing softvare and size of this video takes much GB. I can notupload it on Videoniv but I can upload it on any fileshare.
If you’ll have any more questions, feel free to ask.
I’ll call Apple today and see if they know anything about ‘Screen or Add blending mode or Luma Key for blending’.
It feels like this should be something I ought to be able to do myself in iMovie…
Thank you again!