If your concern is to keep the color from fading, that's genetic, built in to most poodle colors, and can't be stopped.
There are many excellent shampoos as Raindrops said, and there are some products, similar to human color enhancing conditioners, as Ren. said that might add a hint of tint.
There are many excellent shampoos as Raindrops said, and there are some products, similar to human color enhancing conditioners, as Ren. said that might add a hint of tint.