RayRay, baby and child poos come in a huge range of colours and there is rarely cause for concern. Yellow is really normal for bf babies, and green is usually to do with high lactose - so it's common with oversupply, or if the mum changes sides too soon. Most likely you have a really good supply which is causing the green-ness in this case. As long as there are no signs of a problem such as screaming in pain etc, then I wouldn't worry at all.