Humm... at least the thumbnail looks pretty neat. Maybe in the program use colour curve/levels to boost contrast a bit so you could see better? If this is a well-lit and well-exposed reference, then the flesh should probably be a lot lighter, and some of the extremely occluded areas should be almost pitch black. Maybe you could establish the light /dark tones first and paint the rest, so you have the full range to work with. Actually another method you could try now is to use a huge air brush and set it to white/black and use overlay mixing, just glaze on the light/dark part and try make it pop more. A lot of gradient-looking comic shading are supposedly done like this with a selected region...

It's less about your process and more about your understanding of color. It can be helpful to do grayscale first, but it's definitely not necessary. I'd recommend learning more about color in general, and then specifically how it relates to skin tones. There are all sorts of color systems out there, but I find Munsell to be the most useful for artists. I find it more usable than cool/warm. Pay particular attention to chroma—it's the thing people have the least understanding of. But in your piece, the "dead" color is coming from keeping both chroma and hue mostly consistent, and only changing value. Human skin has tons of fluctuations of hue and chroma. Dorian Iten has an excellent video on youtube that I would highly recommend in general, but especially for you. He talks through exactly what I mentioned—and intro to color in general using Munsell, and then more specifically about skin tones. https://www.youtube.com/watch?v=I2z0FnitxT4 I added a super quick paintover where I just threw in a few hue and chroma changes. There's a lot more you could do with this—especially with reference—but hopefully this communicates the idea. Hope this helps!

Hey Tyler, The modeling on this is nice, good job. The reason the colors look "dead" is because all the skin is the same color. You need passages that are cool, you need to lighten colors without using only white, you need to add some more color to your shadows. Ask yourself, Is the light cool or warm? are the shadows cool or warm? same question for the highlights. Look at your hand. It's not just a general flesh color, it has blues, greens and reds. To answer your question, usually people paint in black and white to learn how to control their values in paint. I don't think you have that problem. I think you should look at paintings you like, and really study the color. I'm always surprised at how much pinks, purples, blues, and reds I find in flesh tones of my favorite paintings. Keep at it, your close :)