Changing theme to 'Dark' doesn't change AppBar color

[arx111]

consider:

 <AppBar color={'primary'}>
            <Toolbar>
                ...
            </Toolbar>
</AppBar>

when toggling the theme to 'dark', this doesn't affect the AppBar background color.
Is this intentional?

[povilass]

Mode works only with default color if you want to implement your color you can use sx property.
Here the example code

[mbrookes]

@arx111 This looks like a duplicate of #18308, which is targeted for v5. If you would like to work on it, that would be great!