I found a bag of lemon ochre and that with Bohemian Green Earth brought me a warmer green. A Verona Green Earth from Natural Pigments is a similar pigment and with a smoother grind. It's the sample to the right in the image.
I will need to mull the Bohemian as it is rather clumpy and takes a lot of palette knife work to work smooth. (I still seem to miss some clumps that only become apparent as the paint settles.)
Kremer has a couple of yellow ochres described as greenish so there is soon to be an order for these and more.