That's cool! We missed out on the green beach so I'm glad we got to see it thanks to you! We took the rental Jeep up to a certain way and then we found it was way to bumpy and did not want to make any damage to it either.
We were short on time though so we gave up on the walk as we knew in advance it was a good 1h30. Sometimes you have to give up and you can't see everything!
That's why we consume so much travel blogs then !