Hey! Thank you for taking time and leaving the comment. I felt something is not right with dithering but I couldn't decide what can improve its look. I will try to delete it and change color transitions so that they can be smoother. Also, thanks for mentioning about amount of colors, I will pay attnetion on this too. Hope I will get better. Take care! :)

I think the dithering on the wall is a bit superfluous. The transitions between colors are quite abrupt, yet you use dithering, which just adds noise in this case. Decide whether you want abrupt color transitions (that could be a valid stylistic choice), or, if you choose to use dithering, try to make the transitions smoother.

Also, you could try reducing your color count. Right now you're using 30 colors but given the tone of your piece you could easily reduce your palette to 16 colors or less.

Good luck!