You can dye fabric with walnuts
Jillian Eve used black walnuts to overdye a fast fashion dress. Let the walnuts get a bit soft, but not all the brown. They are really hard when they are green - you could get into them mechanically instead, or boil them to soften them.
Wear gloves!
Enough walnuts to make the dye pot liquid dark brown. I used about 8 total. Aluminum Sulfate at 10% of the weight of the dress when dry. Prep walnuts, extract dye by simmering walnuts, removing walnut hull, continue to simmer kernals for another hour. Strain dye liquid and submerge dress. Simmer for another hour. Let cool then rinse dress. Done!
Remember that overdyeing, and/or changing buttons and the like are all options to help you fall back in love with things you own but don’t wear.