So, the dithering is great, "the colors aren't". It's just my opinion about it, you can improve your palette
if you try switching a bit the lights to yellowy colors and darks to bluey colors, aslo the lighting source of the fire
is good. 
"otherwise, no anyone draws as the same way".
Yeah, I agree. Something here does not feel right with the colors and all the dithering in the world is not going to solve it :). What do you think it is? I think that blue mas in the center, the cauldron, diverts too much. Shall I try using the greys instead? Also, the green lighting on the owl's head feels forced.
I'm not really convinced at all of the color palette, the dith is great.
I'm just liked with the illustration, looks amazing.
The color difference of the background and the PJ background... 
Just kidding, this looks really good!
Thanks for the feedback. I revised the palette, got rid of about 6 unnecesary colors and I shifted the grays to blues. Now It feels easier on the eye.