What color dice for trying to install 4th mod?

By Typherian, in Star Wars: Edge of the Empire RPG

Question Asked by Domingo:
When modifying attachments, does the difficulty increase with each subsequent modification (i.e. Hard for the first mod, Daunting, for the second mod, Formidable for the third mod)?

Answered by Sam Stewart: Yes.

Followup Question Asked by Domingo: Assuming that the difficulty increase is cumulative, what is the procedure for the fourth mod? Are more difficulty dice added beyond five, are difficulty dice upgraded to challenge dice, or is the Impossible task sidebar followed?

Answered By Sam Stewart: The GM is the final arbitrator as to which procedure to use, but generally I recommend that the GM allow the player to make the check, upgrading the check once for each increase beyond Formidable.

I just want to make sure I understand which color dice to use. When I see "upgrading the check once for each increase beyond formidable" I'm not clear on how that would look.

Trying to install the 3rd mod uses 5 purple dice. What does trying to install the 4th mod use? 6 purple? 4 purple, 1 red? or 5 purple, 1 red?

I think it should probably be 4 purple, 1 red as keeping the 5 purple and adding a red seems like a double jump, but if it's supposed to be 6 purple, that'd be even better.

While we are on the topic, what's the dice pool for trying to install a 5th mod? (are there any attachments that have 5 mod options? I'm not sure)

Edited by Typherian
Clarification

Upgrade means convert a purple to a red, and you would upgrade for each subsequent step. So theoretically up to 5 reds, but there aren't attachments with that many mods on them.

Edited by 2P51

I think some lightsaber crystals have somewhere in the neighborhood of five mods. But then again, as long as it's your own crystal, you start at Easy difficulty rather than Hard.

22 hours ago, CaptainRaspberry said:

I think some lightsaber crystals have somewhere in the neighborhood of five mods. But then again, as long as it's your own crystal, you start at Easy difficulty rather than Hard.

Now I could be wrong since I'm away from my books at the moment, but if it's your own crystal you get 1 free mod. Then from the second onwards you start at Hard and progress as normal. The exception to that being if you have the Padawan Survivor talent (Secrets of the Jedi or something like that, bottom of the tree, far left I think) that reduces the difficulty of modding your crystal by half your ranks in Knowledge: Lore, rounded up.

The Ilum crystal has 7 mods.

2× Vicious +1

4× Damage +1

1× Decrease Crit rating by 1