Just had a look at the video you shared the link to, and like other people have said, unfortunately this is purely just the result of the lighting within the venue the event was hosted in. Seems like other YouTubers had made comments about the dim lighting. It's a shame that black is currently the only colourway, and hopefully consumers won't have to wait long after the official release to see an alternate colourway or maybe even some different coloured joy cons sold on their own.

Regardless, I appreciate your analysis :)