i tend to avoid rock, ground, steel, and fighting types, so generally types that were once the physical side of the spectrum. idk i just prefer to focus on fire, water, electric, ie. what was considered special back in the day. i think it has to do with the color scheme though lol i'm not a huge fan of brown.
ironically, one of my favorite pokemon is alolan dugtrio and it's ground/steel and mostly brown. oh well!