Header & footer default pattern problem

Default pattern has path like /wp-content/themes/evolve/assets/images/pattern/pattern_6_thumb.png. In this case we can’t apply background color because thumb file is not transparent. But if we change background url to /wp-content/themes/evolve/assets/images/pattern/pattern_6.png then it would work.

Can you fix it by default in your theme so we don’t need to fix it manually with custom css code? Thank you!