I can't view the video on this comp but the two fish i can see on the preview are mollys?
There are two species of platy, xiphophorus maculatus (the fat one) and xiphophorus variatus. Most fish sold as platies are hybrids between those two species largely but also some swordtail species. Those look like pretty pure variatus. Mollies don't come in that colour, but yes, the black thing in the preview is a molly. If it's the one I think it is, he's stunning. (oh no it's not, that ones a female.)
But why are they both that color? They are females, and they have a very pretty red on them. And they both appear pregnant.
Most of the sunset variatus that I have seen can not be identified male from female by color. Both sexes seem to have the same amount of color so I'm not surprised when yours are that way too.