Adding variable in WordPress shortcode


I have this shortcode [post color="XYZ" width="980" height="610]

I wish to pass $ color in color="". Here, $ color is fetched from dynamic URL: www.mydomain.com/check/?color=BLUE $ color is working fine otherwise, but I wish to pass it in the shortcode so that color is dynamically loaded on the page based on $ color

How could this be achieved?