Red filter strobes?

While watching the making of Blue Planet 2 (Gates and Nauticam commercial) I noticed one of the video shooters with red filters on his lights. I assume this allows some fill light when shooting with a red filter on the lens? Or perhaps it's just filling in the red spectrum of light? Has anyone tried something like this while shooting with red filter or Magic Filter?

Your title says strobes, but your text says video.

I assume you mean video.

Balancing ambient light against artificial light might require some color adjustments.There are some threads on here talking about this.

I saw it used on video but wondered if the technique could be applied to still shooting with strobes.

Yes it can! I use the Inon red filter on my strobes to bring out truer blues. It works. Here is a link to an Inon document that gives an explanation:

http://www.inon.jp/pdf-dl/_userdata/ColorTemFilter_technic-en.pdf