How to digital color a character in the dark?

[Klaustasya]

Hello guys!
Recently i started making a small drawing compilation of my oc's and i wanted to make a digital drawing of my very first male oc in the dark (you knows those kind of cool illustrations where you see a face in the darkness and his/her eyes are shining birght through it? that, that stuff) so i wanted to produce that kind of effect but i'm still sort of an amateur in coloring so i thought about asking here if there are some digital painting tutorials for this theme or if somebody could give me a few technical tips about it (i use clip studio paint ex) like multiply layers or others to create the dark night effect

[Daknight]

Depends on the kind of darkness. If you want say night style with some glow effect from the eyes I would go creating a gradient layer that goes from gray to dark (simulating the moon casting some light, etc) and lower the opacity for the other layers to be seen. Then create a layer on TOP of that one to add effect like luminosity for that nice glow. Here is an example of me using this method.

You play with opacity and luminosity till you find a look that you like.

[joannekwan]

Color theory is your friend!
Whenever I color a nighttime or dark scene, I will usually stay with just blue to violet hues. To portray more yellow colors, I slide the color picker to the desaturated side, closer to grey. Against the other blue and purple tones, your eye will perceive the grey as yellow/brown.

I also omit shading/highlights when there are no strong light sources present.

But sometimes when there is a strong light source, I will keep things a single flat color and only use the lit areas to convey the color of the subjects.

[amortelito]

Great advice from the comment before me. Well if you find it hard to draw with the equivalencies of your day colors in the night palette you can do this:

Color your page like you normally do.

Then fill a layer with a blue of your choice, reduce to opacity of the layer to 60 % or less, and apply in the blending mode of the layer Linear Burn The blending modes are at the left of the layer opacity.

Finally you can correct the colors that you find odd or that look too blue, I always correct the whites because they end up looking blue, which looks a bit fake, I change them to grey.

For the showdowns you can paint a dark blue or black shape with the airbrush and apply Darken Blending mode.
Then in another layer you put the highlights or the shine of the eyes with brighter colors.

I hope this helps.