I finished the line art 2 days ago, but I kinda shot myself with the coloring. The original character (Link: https://housamo.wiki/Tvastar) is really finely shaded, like a painting.
I tried first a normal cel-shaded version, but that sucked, looked nothing like the original. In the end, I was tweaking just the head for several hours, till I got an acceptable version. After that I did the same coloring on the body and here is the first end result:

Which looks nice, but it not fit for animating, as each part has been set up pixel-perfect with gradients. For one image that's fine (tho a painter software would be a lot more suitable for that job), but I cannot just copy-paste it to the next frame. Kinda puzzled now how to proceed. It was a valuable lesson to not du such a coloring in the future, but I still son't want to scrap what I did already.