In negatives I can recommend the following. It's making a nice style:

(loli, greyscale, monochrome:0.5)

I made a LoRA for PonyXL using my old generated images with my sd1.5 models ObsidianV3-Flat and ObsidianV3.3.

Can make some good abstract and colorful stuff.

I also created a model called ObsidianPDXL using this lora.