How to set color of this area in the picture in Simple Theme?

[Saya1]

[ZestardTech]

Hello there,
you want changes background color right.
Please share your store URL and Screenshot.
So that I will check and let you know the exact solution here.

[Saya1]

I don’t want change the whole backcolor, i only want to change the framed part I pointed.

https://www.haljia.com/

Thank you very much