Upgrading Green Weapons

Does anyone know what happens if you try to add upgrades to green weapons? Do they work? Do they overwrite the green weapon's bonuses? Does it stay a green weapon?

For example, I have a green Stinger bow that lengthens poison duration. If I add an Icy bow string to it will it now do Cold damage and still lengthen poison duration? If I add a grip of fortitude, does that get added to the bow? And does the bow then become a green Icy Stinger of Fortitude?

I know I could just try it, but I'm reluctant to ruin a green item. Anyone else tried it?

Thanks!

Assuming you can apply the bow string or bow grip it would replace whatever mod was already present, as the existing mods are either due to a bow string or grip, which, if the item was salvagable would end up being one of the items returned from salvage.

I don't think greens are upgradeable.
That was discussed when the Sorrow's Furnace was 2 days old.
Greens can't be salvaged either.

Can't upgrade, you can't even dye them my warrior needs a pink/green shield

It wont ruin it and a green item is not that rare 2k for a stinger