Hello,

 You need to change the background color in Step 3 - Product List Object in the Settings Tab and so the dropdown list will take the same color of the backgroundcolor of the Object.

Please feel free to write back if you need more information.

Hello!
I Set transparent color, but the color white in the frame. why?

Hello,

These fields are rendered by the browser and they don't allow to have them transparent. You will need to add the background color to the cart object so that it matches to the color you used for the background of the website.

Many thanks!