Thank you very much, gentlemen.
Eric - the green is due to moss. It is especially striking on an overcast day after a spell of rainy weather and depending on the direction of the light, the hues change. This area along the Syðra-Fjallabak (South Fjallabak) route is like another planet. Landmannalaugar lies on the Nyrðri-Fjallabak (North Fjallabak) route, an area of red & orange hued rhyolite slopes.