oh wow, thank you so much.
hope this helped!
I would make the skin a little bit lighter and work with light and shadow.
I like white highlights on dark hair, I don´t have much time but here is a hint
what I mean
They key to coloring is never go completely black or completely white as you have no way to shadow or highlight it. Color theory is using the surrounding colors to make the black seem darker than it is. If you color pic most blacks in pictures, it's not truly black.
I'd pretty much just do something like this.
Or alternatively, you can play around with the color of your outlines. I used white in this draw over example, but it doesn't have to be white, could be any contrasting color.
I think you can leave the skintone as is, but like others have mentioned highlights will add a lot of the dimension. I’m not sure exactly where the light would fall on her face but I hope it gives you an idea of what can help her features stand out more. I’d also recommend looking at pictures/photographs/real life of people with this deep of a skintone to see how the light reflects off their skin.
I followed the contours of the face with a line of highlight but also darker backgrounds will make the skintone also really pop, a blank white background can be cool for a statement piece but the details do get lost, unless I were to maybe boost the contrast more between the highlight by making in lighter. But I think the softer highlight looks a bit more natural!
So definitely the darker background is my secret tip to making the details in the face show a lot more readable 
you can also add texture to the hair with the same paler line, but also if you like the hair solid for a simpler style it could work too.
Hope this helps! It’s fun to see your progress with the new digital paintings ^_^!
I think it will, but i'll have to improve to be able to follow your suggestion at the level you can do it at lol
Thank you, and yeah, that's a good suggestion since I really don't want to lighten my characters' skin to make their features stand out. and yeah, adding details in the hair is definitely a goal because I want it to have more detail as I improve lol. I need to watch some dark-skinned makeup tutorials or something.
It's kinda the trade-off you gotta make with that sort of flat style. You could also design the rest of the characters with a much lighter skin to keep the contrast between her and the rest, keeping that 'essence' intact.
Either that or you learn how to render light and shadows. And then I would suggest following @beebutterbee 's example, since theirs is the most legible.
the goal is to improve my art, and no, the essence still isn't the same even by lightening other characters' complexions. It's still changing the OCs, and I don't intend to settle, just improve.
Yes, I do intend to learn to use lighting and shadows, i'm simply still learning. I have only been drawing digitally for less than a month after all.
The main thing to focus on are highlights.
But also willing to find a medium between how dark their skin is and what is going to be visible.
I like Rainbow High so am going to use them as an example because it's easier to visualize.
Ayesha (right) is the doll with the darkest natural complexion in the series. You can seen how the highlights in her face is what makes her pop. Her skin color is dark but her brows and eye liner are much darker.
Shanelle, who has more of a fantasy skincolor, her skin is more just a dark grey than a pure black.
I would recommend slightly lightening her skin and putting a dark shadow on it.
If you really want to learn, I'd suggest to stop trying to draw your characters in a stylized way for a while and start building the fundamentals. Google image search an entire folder full of reference material of the stuff you want to improve upon and try to just replicate that. The sort of stuff you see @Lensing doing in his studies. Try to understand the underlying construction for anatomy. Try copy a photo as closely as you can by painting it. You'll learn a lot faster and better that way.
Also another thing that helped me when I starting out drawing in color, and I still use this to help me today, is to look at how other artists render what I want to draw. Of course, don’t let it discourage you, this is just meant to inspire. Doing studies of old paintings really helped me learn things that were difficult to draw at first.
This blog has some really get resources for darker skintones btw so I’ll link it to you, I hope you find it inspiring. I certainly use a lot of inspirations from other artists, there’s just so much cool art out there.
I used this old painting and broke it down to take away the colors he used for the skintone. He uses actually just straight up black it looks like for some of the darkest colors. But there’s also a great deal of highlighting, but just have fun with your art right now! You’re starting out with digital so just experimenting helps the most. Sometimes the things turn out and sometimes they don’t but that’s just the learning process :’) Still, it’s really fun to get our characters down on paper … or tablet 
I apologize for always writing novels 
️
https://blkwomen.art/post/677389093139791872/nubian-beauty-tobias-andreae-german-182318732
also learning values first is extremely important! 
it can help you with shading and finding light sources! ill use my fanart as an example hope you dont mind 🥹 @abigaillmartin
i started off with grayscale because doing so makes it easier to think critically
after that i add the color but because i used grayscale theres not one set color if that makes sense 
no need to apologize lol, those are all really good suggestions XD.
@daeygurart that makes a lot of sense, thanks
I don’t mind at all @daeygurart
Hmmmmm. The only characters I have with darker skin is Pujita from Cracking Eggs. I honestly don’t know how I do it.
(Ignore how bad the art looks) T-T
Also I have a new character who is going to be introduced as the new doctor in Smelton Oliver Greenwood
Just like with the rest of my characters I try to give them distinguished noses, eye color, etc.
But unfortunately I don’t have any more examples. I wish I did.
It's fine lol. Complexions of this darkness I don't have much trouble with, I can go all the way up to dark chocolate and I can still see the features, though I do still have to learn more about highlighting, it's when I get into the carob/molasses range that I get lost XD
I disagree with lightening her skin as a stylistic trade off. It's common for black people to not be captured well in photos, but that's an issue with the photographer's skills, not the subject. In that sense, you should consider how you render.
Since you're working with a tone that's deeper, you might want to go about building her up with additive colors as opposed to subtractive colors, which is what we'd typically do. 
This is how iridescence works. It's a diffusion of light on deeper surfaces.
Personally, when I want to convey depth among darker colors, I usually erase the ink and color in that area.
I like to shade/highlight with colors that compliment the character's undertone. I feel what user @beebutterbee suggested is an achievable balance.
With love, saying "I'm still learning" is a crutch. You're always learning, and will always be no matter what you do. You just need to hoan your artistic discipline. That will happen with the willingness to experiment and see what works/doesn't work.
Good luck with your art! <3
So the biggest thing I've learned when it comes to brown skin and especially darker skintones is that it falls between undertones and highlights. I'm still learning the best ways to render these kind of tones for my own art style which is also flat but references and tutorials have helped so I'll just drop some that I've gone back to often here:
https://www.deviantart.com/lurrkingly/art/TUTORIAL-How-I-Color-Dark-Skin-867708572
https://www.deviantart.com/puppsicle/art/Skin-Tone-Cubes-Free-to-Use-842445436
as for your case it may be useful to find a nearest neighbor shade when looking at some of these dark skin tone palettes and build from that, so maybe red or purple undertones like this small edit i did to the base tones and then picking highlights
another thing might be changing the color of the hair a bit so that the lines can read better and so there's clearer contrast like some of these samples i threw together here
obviously it takes a lotta playing around with (these took me a couple hours or so to play around w tones) but it is possible to get deep skintones without sacrificing shades.