sketch

colour lineart (preserve transparency)

colour fill inside the lineart (select outside lineart, invert selection, fill)

blotch shading

blend shading

colour the other parts (same layer cause i like simplicity)

tried using green for shading this time hMMM

added some darker green and yellow

merged colours and sketch, then made an overlay layer on top (used airbrush)

shading with a multiply layer (blue)