chromatic orb and conjure minor elementals

does the damage enhancement from conjure minor elementals count as rolling "doubles" for the purposes of chromatic orb being able to leap to another target?

conjure minor elementals says "any attack you make deals an extra 2d8 damage when you hit a creature in the emanation"

chromatic orb says "if you roll the same number on two or more of the d8's, the orb leaps to a different target...."

assume both spells are doing the same damage type. 

I'd say that "... the same number on two or more of the d8s" refers specifically to the 3d8 damage rolled for the spell, not including any extra damage from other sources.

EDIT: 3d8, or: "Using a Higher-Level Spell Slot. The damage increases by 1d8 for each spell slot level above 1."

I agree with this interpretation, especially since CME was nerfed to not scale by 2d8 on upcast. D&D is supposed to have strong combos otherwise everything becomes homogenous. casters are already punished in this edition with concentration. Johnny Combo player plays casters for stuff like this and is sick of the fun police tying to find a way to take away what is not ambiguous wording because they want to argue about RAI. no combo is RAI, that's part of the fun. when you cut that out you cut out an entire demographic of players. it's not that broken honestly anyway.

"the d8s" definitely refers to the d8s that are only the result of Chromatic Orb.

As for "it's not that broken anyway"... A non-upcast CME means a 5th-level CO guarantees bounces under this interpretation. That's huge.

I agree that the spell is referring to the d8 from the spell itself, and not any outside added damage.

Like, if you have a +2 to the spell always, and then roll a 2, you wouldn't make it bounce, you know what I mean?
It adds damage to the spell but doesn't affect the chance, because that could make it way more likely for every d8 you add.

But you don't have to adhere to the rules; you could always either homebrew/use houserules if you (and/or your DM/players) find this interpretation more fun.
Wizards of the Coast just gave you the base rules so you can have fun. Play DND however you like

I also agree that “the d8s” refers only to the d8s rolled as part of Chromatic Orb. 

However, if the DM does allow it, let’s look at the likely outcomes: 

4th level Conjure Minor Elementals (original 5.5 version, un-nerfed) & 3rd level Chromatic Orb:

- assuming each attack roll hits, the chance per hit of not getting a bounce = 1.9%

- damage = 7d8 = 31.5 average 

- damage on a miss = 0, and no further creatures hit

- maximum number of creatures hit = 4.

Compare that to a 3rd level Fireball:

- damage on a failed saving throw: 8d6 (28 average)

- damage on a successful saving throw: half that (14 average).

 So, the CO+CME combo takes 2 turns to set up, takes a 3rd and a 4th level slots and can cause no damage at  all if you miss the first shot. Fireball takes a 3rd level slot, one turn, could hit more than four creatures and is guaranteed to do some damage (assuming no Fire immunity).  CO+CME does a little bit more damage per hit, has more flexibility regarding damage type and might be able to hit more than Fireball if the targets are spread out in a long, straggly line.

Quote from ThelenyiWhinlaw >>

I also agree that “the d8s” refers only to the d8s rolled as part of Chromatic Orb. 

However, if the DM does allow it, let’s look at the likely outcomes: 

4th level Conjure Minor Elementals (original 5.5 version, un-nerfed) & 3rd level Chromatic Orb:

- assuming each attack roll hits, the chance per hit of not getting a bounce = 1.9%

- damage = 7d8 = 31.5 average 

- damage on a miss = 0, and no further creatures hit

- maximum number of creatures hit = 4.

Compare that to a 3rd level Fireball:

- damage on a failed saving throw: 8d6 (28 average)

- damage on a successful saving throw: half that (14 average). 

 While yes, it "only" does a few more damage on average,  while possibly hitting less creatures than Fireball. Chromatic orb and Conjure minor elementals combined allow you to choose more types of damage than fireball (which is only...fire). The reason that's important is because of the enemy resistances and weaknesses.
It doesn't have a chance to do less damage to enemies due to them succeeding on a save, and it can't hit your allies. Conjure minor elementals can also be applied to other attacks.
This, standalone, is at least a decent combo that's decently versatile. 
Making Chromatic Orb even more likely to bounce due to conjure minor elementals makes this way better because it further reduces uncertainty.

Personally if I were this person's DM, I would allow this because the combo seems fun and creative, and it's better than players constantly casting fireball. It isn't extremely overpowered or anything. But if you use the rules as written, this combo wouldn't be allowed by the rules. 

Thanks. Sorry: I did address some of those considerations in my edited post. 

However, I missed that Conjure Minor Elementals only affects targets within its 15ft emanation, so wouldn’t work on the “long, straggly line” of targets. It also means that you may be best having Spell Sniper, to avoid disadvantage on your attack rolls, as it could be tricky ensuring that all your targets are 5’-15’ away. 

Quote from ThelenyiWhinlaw >>

Thanks. Sorry: I did address some of those considerations in my edited post. 

However, I missed that Conjure Minor Elementals only affects targets within its 15ft emanation, so wouldn’t work on the “long, straggly line” of targets. It also means that you may be best having Spell Sniper, to avoid disadvantage on your attack rolls, as it could be tricky ensuring that all your targets are 5’-15’ away. 

 Ah yes, that is true, I do still feel like comparing most spells to fireball is unfair to the spell. Fireball is kinda just a good spell in general. Also from my memory, some feats or abilities allow you to cast chromatic orb without using up a spell slot at least once

Agreed: Fireball is a high baseline to beat!

Anyway, to answer the OP’s question: if their DM allows the damage dice from CME to count towards the chance of CO bouncing, great. If they don’t, well, they are fully justified by RAW.