In Dead Island, the items you pick up in the game like flares that are green-coloured in your item menu, are they just high-end items to sell or are they used for anything special?
Some will be used for mods, most you can sell. I played this for PS3 and had TONS of blue and violet weapons. I sold almost every green weapon or item I came across being I had either found or made enough weapons that were way more powerful than any of the green stuff I was getting.
Also, side note, I had at least 3-4 orange, only liked one of them.
The colour indicates the rarity. Green items are rarer (and more powerful) than white items, but less than blue, purple, or orange items.
They can be used for various things, from crafting, to weaponry, etc.
The Dead Island wiki explains it like this:
There are a total of FIVE different levels of rarity for an item in Dead Island. These are:
White (Common) - Absolutely everywhere, most items and weapons are this color.
Green (Uncommon) - Frequently found in chests and given as a reward from quests. Uncommon items are occasionaly dropped by zombies on death.
Blue (Rare) - Often given as a reward from quests but can be found on zombies after death and in chests although the chance is low.
Violet (Unique) - Occasionaly given as a reward from quests but can be found on zombies after death and in chests but the chance of this is very low.
Orange (Legendary) - Rarely given as a rewards from quests and is both rarely dropped by zombies on death and found in chests. Finding one of these is truely a gem, congratulations if you have one.