Is it really hard to maintain ash-toned hair dye?

Ash brown looks so pretty, so I want to do it.
I'm hesitating because I've heard a lot of people say the color turns yellow as it fades.

There are also people who say you absolutely must use color-correcting shampoo.
I'm hesitating to dye my hair because I heard it's really hard to maintain.

It's a color I want to try at least once before I get any older, so I keep thinking about it.