Trouble
I failed again...
I coated the parts again and again.
So the coating become too thick that it peeled off from the surface.
I tried to restore the parts to the former state.
But they got speckled...
Top Coat
I coated the spotted that parts with Modeling-Paste.
I diluted the paste with water and mixed a bit of scarlet red and yellow.
And naphthol crimson and blue were needed very very a little.
Coat the parts and wipe them with wet cloth.