REMOVE

1. houses
2. black
3. orange
4. green
5. oil paint
6. machinery

WHAT

1. Visual Works (hierarchy n … (1)
2. artists (visual artists) (1)
3. beards (1)
4. black-and-white film (1)
5. coats (garments) (1)

More 

WHEN

1. 1960 (1)
2. 1975 (1)
3. between 1960 - 1975 (1)