Thanks to all of you who have replied, now here's what I am hearing and what I am wondering.
It seems that pretty much every one loves Old Olive, but no votes for Wild Wasabi.
I don't use DSP much so the only Stampin up pack I have has pinks and grey rather than the green. I hadn't been looking at Certain Celery as I thought it might be too light and maybe too yellowy.
Now I know the colours in the page only give you an idea of the final colour as it is hard to get it right on the printed page, but I was wondering if Old Olive is a bit muddy. In the catty Wild Wasabi looks to be a much clearer green.
And yes I did look at Gumball Green, but two things put it out for me. One was that the green might be a bit bright for what I am looking for, and the other is because it is an in colour, and I am looking for a base green that I can use for many years to come. Now I realise that Stampin Up could well have a big shake up and bring out all new colours, but right now I knom Gumball Green only has a limited life span.
So now yes based on what I am hearing I am leaning towards Old Olive and that will probably win, but I am also why noone likes Wild Wasabi. What am I missing with that one.