I make my own color conditioner to ensure the best possible color match.
It's easy and cheap to make. Just combine demi color with your preferred conditioner in a 1:5 color:conditioner ratio.
Use a 10 vol developer to mix the color *and allow it to develop overnight* before combining with the conditioner. If you don't have 10 vol developer, you can combine equal parts 20 vol developer and water to make 10 vol developer.
I've found B2N too green-toned, as it's meant to cancel out red tones. Their color selection is also very limited, and i don't care for its conditioning properties. If unwanted red tones are a problem you can request "no red tones" on custom orders.