How override modifiers in nested rules

Question

I have a question concerning BEM specificity. I want to be sure to use that methodology in the best way possible. Lets say I have generic style for a headline applying a color. Then my parent container has a modifier that edit the background. I then need to override any subsequent color rules applied to that headline in order to prevent contrasts problems but also probably a whole set of other elements.

How do I extrapolate this issue to much more complex situations? I know I could only override all the styles manually but is there a better way to handle it in the BEM methodology? Is that even an issue?

CSS

.headline{ 
    ...
    color:#513252; 
    ...
}
.section--bg-purple{ 
    background-color:#513252;
}

HTML

<section class="section section--bg-purple">
    <h1 class="headline headline--main">Lorem ipsum</h1>
</section>

I somehow did something like that in my LESS, but I am not sure if there is a better way:

.section{
    ...
    &--bg-purple{
        background-color:@c_purple;
        [class^="headline"]{
            color:#ffffff;
        }
    }
    ...
}

Answer 1

I would prefer to use mixin .section__headline here.

html:

<section class="section section--bg-purple">
    <h1 class="section__headline headline headline--main">Lorem ipsum</h1>
</section>

css:

.headline{ 

    ...
    color:#513252; 
    ...
}

.section{
    ...
    &--bg-purple{
        background-color:@c_purple;
        // here it is
        .section__headline {
            color:#ffffff;
        }
    }
    ...
}