JSFiddle - React, Tailwind, and code Playground

JavaScript

fix = a=>(b=[...a],d=0,e=b.map(f=>f=="roygbp"[d%6]?'n'[++d&0]:'e'),eval("for(i=e.length-1;i&&b[i]!='p';e[i--]='e');e.join``"))

console.log("gorboypbgbopyroybbbogppbporyoygbpr")
console.log(fix("gorboypbgbopyroybbbogppbporyoygbpr"))
console.log("eenenneennenennneeeeneennenennnnne")

console.log()

console.log("prrrrrrgb")
console.log(fix("prrrrrrgb"))