it is in the south of Fuchsia City. the gym leader is Koga.
It's erika the grass type user. the badge is the rainbow badge
The sixth badgeno actually it the third badge
Erica in Celadon City.
Go to celadon city.
after you get the thunder badge talk to officer jenny
Get the Thunder Badge And Talk To Jenny And She Will Give You One
Strength will activate when you get the RainbowBadge.
When you get the second badge from Misty, Pokemon you receive in trades up to level 30 will listen to you., while Pokemon with the same ID as your Yellow Version will always listen. When you get the fourth badge from Erika, Pokemon you receive in trades up to level 50 will listen to you, while Pokemon with the same ID as your Yellow Version will always listen. When you get the sixth badge from Sabrina, Pokemon you receive in trades up to level 70 will listen to you, while Pokemon with the same ID as your Yellow Version will always listen. When you get the eight badge from Giovanni, ALL Pokemon will listen to you, no matter what level or what their ID is.
in a house in Cerulean City after getting the Thunder Badge
Defeat Gym Leader Blain on Cinnabar Island.
It's in Celadon City and you obtain the Rainbow Badge.
talk to officer jenny after getting the thunder badge