import a variable from a _partial.scss file and use it within method in SASS

I'm starting to work with SASS and I'm having problems with partial file structure. By my understanding, I did something like this:

_colors.scss

$red: red;
$blue: blue

_buttons.scss

@import "colors";

button{
    background:$red;
    color:$blue;
}

_style.scss

@import "colors";
@import "buttons";

But using this SASS is showing error saying that I can not use the variables already found in the _colors file ... how to solve?