Daniel, let me see if I can explain myself a little better. Again, this is all about the process - there are many ways to achieve a pleasing result. Your "journey" with the color white is a perfect example. It is less about "right" or "wrong", and more about "how".
Priming smaller figures in black serves one major purpose for me - the deepest shadows are already in place. In many cases, very little of the black is visible at the end - seam lines on coats or pants, around buttons and cuffs, and so forth. I use Vallejo and Andrea acrylic paints, and a water mixture that has a couple drops of dishwashing liquid in it.
If I'm painting a British red coat, I start with Vallejo Black Red [859/035], and cover everything except seam lines, under pocket flaps, etc. Then I will use successively lighter shades [Burnt Cad. Red 814/034; Carmine 908/030; Flat Red 957/031], always doing a 50-50 mix when I introduce a new color, and paint less and less of the figure, until I am using Vallejo Scarlet [817/026] for the highest highlights, like the tops of creases that would catch the sun at noon on a clear day. In this way, I feel I have better control over the contrast between each shadow and its corresponding highlight. The undersides of sleeves are maybe one shade "up" from the first coat of Black Red. The tops of the sleeves may have three or four shades layered on, to get to the highlight I want.
In a similar manner, my whites are really a series of greys and tans. I sort and store my paints according to my perception of "warm" or brownish greys, and "cool" or blueish greys. (I think I own a bottle of White, but I can't remember the last time I used it, and it is probably rock-hard by now!) To paint the pants of your French fusilier, I would start with one of the dark greys [Black Grey 862/168 or German Grey 995/167] and paint almost everything. I would progress to Neutral Grey [992/160], Dark Sea Grey [991/159], Stone Grey [884/104], until the highlights in Deck Tan [986/110]. For a dress uniform, I might start with Neutral, and end with Ivory [918/005].
I'm guessing this reads as a laborious, time-consuming process, but I assure you - it takes longer to type it than it does to do it! I'm using very small amounts of paint - 2 drops for the darkest grey or red, then 1 drop of the others, and I'm painting smaller and smaller areas with each step. I mix between colors on my palette to get my blending and transitions as smooth as possible. I've learned to stop before I've gone "too light", and switch to another part of the figure - I can always go back, after the paint has dried, and add a highlight or two. Many acrylic paints will dry slightly lighter than the wet color you see on the palette, and the amount of water used will also impact the color slightly. I also look at the figure under different light sources, as I get close to the end, to see how it looks. If the contrasts are unpleasing, I'll wash the coat or pants with a mid-range shade, and adjust from there.
My first figures were painted with PollyS acrylic paints, basically blocking in the main colors, and only occasionally trying to use shadows or highlights. Then I fell in with a great group of painters, and they encouraged me to switch to oils. I learned about color theory, mixing you own colors, blending, and shadows/highlights. When Vallejos became available, I used them for undercoating. But I saw the amazing results the so-called "Spanish Painters" were getting with the acrylics, and I wanted to learn that method, too. My early attempts were trash. I just didn't understand. I was about to give up when I discovered the AWI 28mm figures from Foundry (sculpted by the Perry twins), and read about the prime-black-paint-up methods that gamers were using to paint these figures. I tried this method, and for some reason it made sense. I've painted both small and large (75mm and busts) with this method, adjusted a bit for faces and metallics, for the past several years now, and I'm very comfortable with it.
I hope my explanation will be of some use to you.
Most importantly, this is not to say that one method is "better" than another. You have achieved enviable results with your painting, and I admire your effort (and courage!) to display your WIP images so that we may share your process with you. You have an obvious passion for 18th Century French troops, and it shows in your work. Thank you for sharing that passion with us! Don
