Coloring

I was looking for a way to simplify my process and being able to start from a greyscale
would be a nice alternative. Here are the results of the tests I did.

1. Fully opaque BW base.
2. Here I put BW, set to Hard Light, above the colors. I was tempting because it allowes
    to give a tint of color to shadows, but it wasn't preserving original values at all.
3. The most common technique is to set colors to Color mode. First problem is that there
    is no hue shifting which makes the colors mudy or flat. The other problem is that it
    doesn't preserve values perfectly because the most saturated blue, turned to BW, will
    be darker than the most saturated yellow.. BUT! I found out that there is Color HSL
    mode (at least in Krita) which won't change the values at all!
4. I still wanted to unify my shadows so I did the following: I created a layer above filled
    with color I wanted my shadows to be, and also set it to Color HSL. Then I copied my
    base BW sketch, inverted it (to make my shadows white) and turned it to a transparency
    mask, that I applied to the layer filled with color. The last thing was to adjust Levels of
    the mask and color and opacity of the colored layer.

And now I have the resault that I'm pleased with. I'm already using it for my next
painting. I hope it will be a good foundation for overpainting. I also hope it will help some
of you guys.

done with Krita