+3 for the other colored slots
+3 for the other colored slots
Hmmm... But only +2? No.
Nice idea, but look, a colorless slot equals a +6 ability score, or some of the higher level abilities for the other colors, etc. Which is way more than +2!
So nice idea, but make sure it's fair, and I'm okay with it. Don't see it ever happening, but I'd be okay if it were a bit more in line with what a colorless slot is worth.
OK for accessories and armor (I'd go +3 colorless/+4 for others, though). It doesn't need to enable crafting +6 stats into that slot since you can already put +6 stats in those slots without going through crafting. There are plenty of +3 and +4 enhancements I'd rather have than another +6 stat.
Highly overpowered on weapons. Even just +2 gives an ESoS Holy, and the opportunity to break boss DR with the red slot.
One possible solution: give +3/+5 on everything, but the craftable can only be used on "Trinket" effects when applied to weapons, like rune-arms. That allows for extra effects, but not ones that massively boost weapons. This would apply to the craftable weapons being added to the challenges, as well.