Hello guys im creating an admin panel where you can delete images. What color should I use on these buttons that are in the background of a photo? As you can see it doesnt look super great if the kitten is red-ish in color. This is how it is now:

Having a 2-color symbol of some sort would fix this (ie a white circle around the trashcan). That said:
You may want to do some forward-planning here. Right now, you can delete, but I imagine in the future you may want to be able to replace, rename, reorder, adjust, edit, download or some other operation. In this case, you'd quickly fill up the space of the photo with icons.
As such, the way this is usually done is by adding a checkbox to the image which you can check, and have a dropdown somewhere on screen with bulk actions across all selected content. Check how the photo album on your phone handles this issue for direct inspiration!