If you're talking about the Sevii Islands, and you're talking about LeafGreen, just go to Vermilion and talk to the guy on the dock. He'll ask you which of the islands you want to go to.
If you actually ARE talking about Pokemon Green, which is unlikely, because it's a Japanese-exclusive game that isn't even sold anymore, I assume it's the same thing, or at least similar. Pokemon Blue and Red (english) are based on Pokemon Green and Blue(japanese), and Pokemon FireRed and LeafGreen are based on Pokemon Red and Blue(english). Maybe some lost in translation stuff going on, but you'll figure it out.
You get the Rainbow Pass from Bill in order to have access to the other four islands in the sevii islands.
Usually you can find it in seafoam islands.
Johto is inaccessible on Leaf Green although Islands Four to Seven contain Johto Pokemon.
Cinnibar island, Fuschia city, the Pokemon league and two island and the other islands.
use an escape rope or the TM dig
Seafoam islands.
if this is for leaf green i think no Pokemon are on 7 islands but islands 8 and 9 there are lugia and ho oh good luck
you get to the sevii islands after you defeat the Pokemon leagu
You eat a taco then you use the methane gas that comes out of your butt and fly back
You get the Rainbow Pass from Bill in order to have access to the other four islands in the sevii islands.
Usually you can find it in seafoam islands.
Green shards are found underneath the water (or in the sand on islands) while diving.
You go to ranbow islands and go to the resercher guy and then go to sevii islands and u verse mewtwo and legondary Pokemon
Johto is inaccessible on Leaf Green although Islands Four to Seven contain Johto Pokemon.
there is no island 8 or ninie in Pokemon fire red or leaf green or any other Pokemon games.in fire red and leaf green there is only islands 1,2,3.get further in the game and you'll go to islands 4,5,6,7.
Cinnibar island, Fuschia city, the Pokemon league and two island and the other islands.
from vermillion city where ss anne was