Where is Grandma’s House (this may be the title, or similar). A little boy is looking for Grandma’s house. He goes to many places looking for her. This children’s book is illustrated with full-page paintings or lithographs with unusual “noise” in all of the colors: many tiny particles of different colors within each main color, as though covered in non-shiny nano-glitter or mini-crystals of multicolored salt.
I think the little boy’s name is Willy.
Could it be Anthony Browne’s “Into the Forest”
The illustrations seem to fit. Cover image:
https://archive.org/details/intoforest0000brow