this programm does not respect material colors and shape???
It’s an AI image generator, no, it makes ■■■■ up as it goes along.
If you want photorealism you will need to use a proper rendering plugin.
I drew a cube with a tapered cylinder beside and tried to get Diffusion to produce a watercolor of a lighthouse upon a rocky prominence, on a blustery day with a sailboat in the background. I specifically told it only one lighthouse.
It repeatedly showed other lighthouses in the distance and refused to put the foreground lighthouse on a rocky shore. Most times the lighthouse was stuck in the water. Sometimes upon lonely rock separated from the shore.
I gave up.
Don’t forget that this is a relative new extension that is still in Beta-fase…