Black is one of the hardest colours to get right. A really deep black takes heavy dye, long baths and a lot of water.
A couple of seasons ago we started asking which pieces actually needed it. It turned out to be far fewer than we thought.
Ivory, stone and fog are just the colours our wool and linen already are, with a light wash. They age gently and don't need any dye at all.
We kept black where it really counts. The column coat, the loafer and the cap. Everything else is the colour the fibre came in.