change primary slidebar background

I hope you are adding those changes to either a child theme or a custom css plugin! any changes you make directly to the theme will be lost on update.

As for your query, you need to target the .site:before and #secondary to change the color of the left sidebar.

Better still, just use the Style: Ridizain plugin available for free here: https://ridizain.com/ridizain-styles/

Regards,
Zulf.

Thanks Zulf, great suggestion. Will certainly use a custom css plugin.

No problem and all the best ??

Marking thread as resolved for now.