I'm using the Pixel launcher, you need to install it as apk, and it works fine (allow unknown sources in security settings).
Clean UI without any Ads...

Matioupi wrote:

Launchers (at least Nova) do not change icons in the setting menu

then that you do not like the icons in the settings it does not mean that they do not like everyone!
accordingly, company representatives Blackview can not fulfill your request because these icons are an integral part of the shell of a specific model!
Many brand companies use their branded graphics shell in android and there is nothing terrible in this
I could do a patch that will replace the icons in the settings for the standard ones or those that you provide, but it all depends on how much you need it !?
if this is what you really need, if you have TWRP on your phone, then contact me on the website xda or 4pda and I'll try to help you

I ask you to excuse me, I do not know English, and the online translator does not translate everything correctly

I don’t like white backgrounds on my menus, phone dialler, messaging app etc…
There’s a new theming engine called substratum.. while I was trying out dark themes I found allot of them were changing the system icons

so It might be something you’d like to check out?

Video example of themes

Substratum Theme Engien App (free on google play)

Asking the tech team to provide stock icons can be possible. I will forward this request to them.

Sorry guys, our tech team can't implement this feature at the moment.