Hello @motanujora ,
To remove the gray outline on product media, you can simply follow the below steps.
Go to Shopify Admin Dashboard and click on Online Store.
Click on Customize button.
Click on the theme setting icon in the left-hand sidebar > Then click on Media.
Make border thickness 0px.
Refer to the below screenshot for more information.
Hope it helps. Let us know if you need more help with this.
Regards,
CedCommerce