ISO-8 are used to upgrade Skills, Specials, and Abilities.
There are seven different types of ISO-8:
yellow,
white,
red,
green,
blue,
pink, and
violet.
Sources for ISO-8[]
ISO-8 Red:
- ISO-8 Challenge - Red (Battle with
Thor) - ISO-8 Challenge - Materials (Battle with Vision)
- Orb box: get 3x when pulling a duplicate Tsum
Used for upgrading Skills/Specials of 
Power Tsums.
ISO-8 Green:
- ISO-8 Challenge - Green (Battle with Star-Lord)
- ISO-8 Challenge - Materials (Battle with Vision)
- Orb box: get 3x when pulling a duplicate Tsum
Used for upgrading Skills/Specials of 
Blast Tsums.
ISO-8 Blue:
- ISO-8 Challenge - Blue (Battle with Hawkeye)
- ISO-8 Challenge - Materials (Battle with Vision)
- Orb box: get 3x when pulling a duplicate Tsum
Used for upgrading Skills/Specials of 
Speed Tsums.
ISO-8 Pink:
- Any Battle
Used for upgrading Skills/Specials/Abilities of all Tsums.
ISO-8 Violet:
- Any Battle
- Reward box: get 1x when pulling a duplicate Villain Tsum (earned in Battle)
Used for upgrading Skills/Specials/Abilities of all Tsums (higher levels).
ISO-8 Yellow:
- Stage missions: get 1x for any new
- Event missions: get 1x for any new
- Missions: get 5x for every 5 Battles played with a new Villain (until 99)
- Coin box: get 1x when pulling a duplicate Tsum (~66% chance)
- Alliances: get 5x on every 5th alliance day
Used for upgrading Skills/Specials/Abilities of some Tsums.
ISO-8 White:
- Stage missions: get 1x for any new
- Event missions: get 1x for any new
- Coin box: get 1x when pulling a duplicate Tsum (~33% chance)
Used for upgrading Skills/Specials/Abilities of some Tsums.