Celadon city. You can get there by following the underground path on the West of Lavender town.
Erica in Celadon City.
At celadon city.
You need the rainbow badge which you get a celadon city Hm cut is needed.
It's in Celadon City and you obtain the Rainbow Badge.
the fourth gym is in celadon city at the bottom left of the city. the gym leader is erika. the badge is called the rainbow badge
The Rainbow Badge is awarded by the Celadon City Gym Leader. The gym is placed at the bottom left of the city.
rainbow badge by erika
After beating Lt. Surge at Vermillion City and acquiring the Thunder Badge, make you way to Celadon City to win your Rainbow Badge from Erika.
You get it in Fuschia City from the warden in his house in the bottom right corner of the city, but you have to have the Rainbow Badge first to use it.
Head west of Celadon to the cycling road, from there go to Fuschia city to battle Koga.
In Celadon city.Celadon City, Leader: Erika. Specialty: Grass. Prize: Rainbow badge.
Heart Gold After getting the 8th badge go to Ecrutek City and fight the kimono girls in the dance studio. Once you beat them they will give you the rainbow badge. Soul Silver When in Kanto, go to Pewter City. The man standing on the raised surface will give you the rainbow wing.