user29763: It is some kind of body glow, either blue or red with big 'chiaroscuro', everything else being black
https://imgur.com/gallery/INHDlt6
that'd be mega helpful for me, you'd make my day :))

user26178: You need a video editor that let you add curves to your video. Davinci Resolve is a great option.

Convert it to grayscale, you can simply reduce the saturation to 0.
Invert the curve. Augment the contrast making the curve more vertical.



Bring the green and Blue channels all the way down


Play a bit more. But that is the idea.


Option two for the final color is to add a color rectangle with different blending mode in the editor.

https://pixabay.com/es/photos/verano-flor-cabello-retrato-cara-4246927/

29763: <p>It is some kind of body glow, either blue or red with big 'chiaroscuro', everything else being black</p>

<p><a href="https://imgur.com/gallery/INHDlt6" rel="nofollow noreferrer">https://imgur.com/gallery/INHDlt6</a></p>

<p>that'd be mega helpful for me, you'd make my day :))</p>
 26178: <p>You need a video editor that let you add curves to your video. Davinci Resolve is a great option.</p>

<ol>
<li><p>Convert it to grayscale, you can simply reduce the saturation to 0.</p></li>
<li><p>Invert the curve. Augment the contrast making the curve more vertical.</p></li>
</ol>

<p><a href="https://i.stack.imgur.com/J9xYT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/J9xYT.png" alt="enter image description here"></a></p>

<ol start="3">
<li>Bring the green and Blue channels all the way down</li>
</ol>

<p><a href="https://i.stack.imgur.com/4Hbyp.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4Hbyp.png" alt="enter image description here"></a></p>

<p>Play a bit more. But that is the idea.</p>

<p><a href="https://i.stack.imgur.com/jA8NN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jA8NN.png" alt="enter image description here"></a></p>

<hr>

<p>Option two for the final color is to add a color rectangle with different blending mode in the editor.</p>

<p><a href="https://i.stack.imgur.com/H6Xcv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/H6Xcv.png" alt="enter image description here"></a></p>

<p><sub><a href="https://pixabay.com/es/photos/verano-flor-cabello-retrato-cara-4246927/" rel="nofollow noreferrer">https://pixabay.com/es/photos/verano-flor-cabello-retrato-cara-4246927/</a></sub></p>
