Get shortcode attribute value to another function

I am trying to get shortcode attribute value to another function to add inline style.I want to use $color‘s value to another function.

Here is my code

<?php

/**
* 
*/
class MakeShortcode
{

    public $color;
    public function __construct()
    {
        add_action( 'init', array($this, 'PostBLock') );
        add_shortcode( 'PostBLock', array($this, 'getpostblock') );

        add_action( 'wp_enqueue_scripts', array( $this, 'inlinestyle') );

    }

    public function getpostblock( $atts ){
        extract( shortcode_atts( 
        array(
            'section_color' => '#000000',

        ), $atts) );

        $this->color = $section_color;

        $output = 'First LIne';
        $output .= 'Second Line';
        return $output;
    }
    public function inlinestyle(){
        wp_enqueue_style(
            'custom-style',
            get_template_directory_uri() . '/css/style.css'
        );
        $custom_css = "
            div[data-id=289374].post-block-post-left.active,
            div[data-id=289374].post-block-post-right.active{
                background : {$this->color};
                border-color : {$this->color};
            }";
        wp_add_inline_style( 'custom-style', $custom_css );
    }
}
$test = new MakeShortcode();

But background and border-color becomes empty.That means i am not getting $this->color value in that function.How i can get that?