The following order of items quality is fairly well known.

rainbow > purple > yellow > blue > green > grey

There's also certain bonuses that only apply to certain item types.

Since many people have commented that the yellow they see are often better than the purples/rainbows they get, could we allow players to extract one of the bonuses from the item and apply it to another of a lower quality?

Example:

A purple weapon has 1% health steal.

For a fee, the weapon vendor allows me to extract a 1% health steal rune from it.

For a fee I imbune my current yellow item with the 1% health steal.

My yellow item is now a purple item that has the 1% health steal on it.

Restrictions.

1) Only one rune will be extracted from an item. If multiple bonuses exist, a random one will be chosen.
2) The item will be destroyed when the rune is extracted.
3) The rune can only be applied to an item that is a single rarity rank lower. Mythic to Purple, purple to yellow, yellow to blue, etc.
4) The rune will have the same level requirement as the original item it was extracted from. Applying it to another item will INCREASE the level requirement to whichever item has a HIGHER level requirement. e.g. Applying a LEVEL 20 purple rune to a LEVEL 18 yellow item will make the new item a LVL 20 purple item.
5) A rune can not be applied to an item if that item already has the same or a similiar bonus. No +Str on something with +str on it already. There may be other mutually exclusive bonuses only the developers would be aware of.

Many people are stuck with yellows because the purples they do find doesn't give them anything useful. health steal on wands and bows do little for a 2h fighter. It would be great if we could still benefit from finding purples instead of just selling it or giving it away.

I agree-ish.

Just an FYI, an idea like this (and one for 'deconstructing items') was brought up months ago.

Not saying it's not a bad idea, just saying it's something the testers have brought up before.

So, the complaint is that youre not finding purples with the modifiers you want? At least compare apples to apples. A purple item of the same type and lvl will have better stats than a yellow. But yeah, a lvl 25 pruple warhammer with +12 str / +12 end might not do as much dmg as a lvl 25 yellow warhmmer that adds +24 str. Is this surprising to anyone?

agreed, i've upgraded every yellow item i've had to purple, it just had to be of the same template.

I usually look for str or str/end split 50/50. Then I look for +% melee dmg, +% crit, + crush dmg (i stick with a 2h warhammer), after that its a toss up. I also prefer to have 1-2% mana steal. The actual type of armor doesnt matter to me (though I refuse to wear crystal). I end up with a mix of scale mail and ornate/shadow plate.

I usally clear the 2nd lvl of stage 3 in HDoL until I find the portal guardians. Those 2 bosses drop 3 purples each, everytime, so once i get there, I'll kill them, let the pack respawn, repeat. I may find 1 in 30-40 purples I would consider using.