Yes
Well I'm guessing it's the same as Heartgold so first you must have beaten all the jhoto gym leaders but Clair. Then Defeat Team rocket at the goldenrod radio tower. Then the director will give you the rainbow feather. Same thing in Soulsilver but a silver wing.
defeat team rocket in the radio tower scheme an then you get the rainbow feather. but wait, there's more you have to get all joto badges then go see prof. elm. then you have to defeat five kimono girls
You get the rainbow wing from the radio tower director after you get rid of team rocket. (Same thing in soul silver).
There's a guy in Pewter City. He's not in a house or building, just on a patch of rock near the east exit. ;D
pokemon heart gold
for heartgold after you beat Claire go to the dance studio with the komono girls, for soulsilver there is an old man in pewter city
Not at the end of the rainbow- since there is no end to a rainbow.
in mahogany town beat team rocket then go to goldenrod city and beat team rocket there too then you get the silver feather or if heart gold you get the rainbow feather see i know this because i beat the game already
In navel Rock
You son of a... Dumb a#$
You receive it after rescuing the Radio President
i don't know about a gold Pokemon but magikarp when it is shiny is gold