Half of what makes form, compositions, and lighting work is values. So if a painting with multiple light sources, or a complex mood and palette throws you a curveball and prevents you from just painting, try concentrating on just three values, because you can always add the tricky colors later. As is the case with this painting, which actually started as a quick sketching practices, but turned into a full fledged painting.
So below, I wanted a warmer piece...so I decided on the low saturated purple as the mid-tones for the face. I also wanted the main light source to be like an orange sunset...and the shadow, tinted to a dark maroon.
As you can see from the brush strokes, I have the stylus pressure set to opacity only, not size. Putting size on is a great way to get details later....but I find it frustrating when blocking in areas of paint. I was looking in a mirror also for the facial expression, with only a desk lamp on, during the afternoon.
You'll notice above that for the face, all there is, is purple for the mid-tone, dark reddish brown for the shadows, and the yellow for the highlights. Now take a look at below:
A little more colorful. Paint with three values (local color tinted by environment, highlight, and shadow color), then what was added, was a layer on top of our painted layer, but it is set to COLOR. I painted just faded, big strokes of bright orange, over on the left of the face. Another layer was set to HUE, which I painted the bluish tint on the shadow areas of the face. I try to get the colors right, and then add these layers for adjustments. It doesn't always work, it's just an option and way of trying out different tints, texture, and nuances - throwing some "paint" around on a different layer so you don't muck things up :)
So we've got our layers from top to bottom like so:
The Hue layer is optional. The main ones I keep going back to are color, and overlay. Now, I added those layers just to see how it could turn out. I will continue painting in the Normal layer, with the others turned OFF, so I can keep blocking in the local colors, again, just concentrating on my original color selections. I will then turn the extra layers back on, and continue trying new splotches of color adjustments.
Although I never paint with the Color and Overlay layers set to Normal. Here is what they look like when on Normal, without the painting underneath:
Remember, you can always down the opacity of the layer, and we'll be adjusting Levels and Saturation later....it's important to just keep it in drive, and keep painting.
But with those layers back on, we have this so far: