Hi @DaveyAlcatraz ,
You can re-upload your image and then follow these steps to make the background a gradient
1, Navigate to Online Store > Themes > Edit Code.
2, Locate and open the theme.liquid file.
3, Paste the code snippet provided below right before the closing head tag, then save your changes.
#mainContent .hero {
background: linear-gradient(90deg, #606C38, #283618);
}
Like this
Here is the result
We hope this assists in resolving the issue.
If you find our solution helpful, kindly consider Liking and Marking it as Accepted. Thank you!

