Darkening black hair with blue

[bitter]

I've been considering dying my hair for a while. Virgin asian hair, I have a lot of red tones in the sun and I don't like it. (probably like level 2 or 3) I want to go darker.
I was thinking of dying it blue as the blue will cancel out the warm tones and it'll be very subtle on black hair. And when the sun hits, the blue shows a little bit.
Probably not henna-indigo, I don't know if black-black hair would look good on me, just less warm tone and slightly darker.
The brown is subtle, but I'm annoyed by it still. I'm hesitant as once you dye your hair, you have to dye it again and again to avoid patchiness and I'm also wary of damage.
Anyone have experience with this?

[bitter]

Also, my ends are lighter than my roots, probably sun damage my hair is only shoulder length

[Bat]

A basic black would do the trick you can get semi permanent that washes out over time, blue wouldn't really show and blue fades really quickly. Also if you have alot of red something with a green base would be better at neutralising

[bitter]

How quickly does it fade? I don't use shampoo so it might fade slower than normal. And I'm scared a basic black would be too heavy, and I just like the color blue

[Bat]

How quickly does it fade? I don't use shampoo so it might fade slower than normal. And I'm scared a basic black would be too heavy, and I just like the color blue

Semis can last up to roughly 3 months but might be longer if you only condition.

Dye darkens hair so you could probly just use a level 3 you could also just do a stand test with a blue and See how your hair takes to it

[Aerya]

As Bat points out, you need something green based to cancel out red tones. If you want blue, maybe one that leans more towards green? I would also add that it might be wise to do a strand test prior to colouring your entire head, just in case it doesn't work out as planned. That way you can also check how long the colour lasts, that it washes out over time, and how the grow out process will be.