Each move of type A hits a Pokemon of type B (or dual-type B/C) with a multiplier:
x4 (double super-effective): the type is x2 vs both defensive types → bright green
x2 (super-effective): x2 vs one type → green
x1 (neutral): no modifier
x0.5 (resisted): one type resists → light red
x0.25 (double resisted): both types resist → red
x0 (immune): type immunity or ability (Levitate, Water Absorb) → black
Items like Occa Berry (Grass -> Fire x0.5), abilities (Earth Eater vs Ground x0), and weather also factor in.
Domande frequenti
Which Pokemon is immune to the most types?
Shedinja with Wonder Guard is immune to all non-super-effective hits. Among non-Shedinja, Type Null / Silvally / Arceus with the right plate can change their immunity dynamically.