1. Open Photoshop. Go to the top-menu and click File >> Open to open white-grey product image
2. Fix tone and color issues by adding contrast. To do that, go to Image >> Adjustments >> Level.
3. Next, select Magic Wand Tool from the left side-toolbar and tap on the background, i.e., outside the product image.
4. Select CTRL + J to create a duplicate layer. (You will see a new layer - Layer 1 - appearing in the Layer Panel located towards the right)
5. Go to Layer Panel and select Background layer. Again, select Magic Wand Tool and tap on the background. Go to Select >> Inverse (CTRL + SHIFT + I) to remove the background.
6. Select CTRL + J to create another duplicate layer. (You will see a new layer - Layer 2 - appearing in the Layer Panel located towards the right)
7. Go to Layer Panel and select Background layer. Fill background color. Select Layer 2 and reduce Fill to 50%.
8. Now, brush your product image. To do that, select Eraser tool from the left-side-toolbar. Go to top sub-menu and set Opacity to 15%, Brush Size to 180, and Hardness to 0. Start brushing.
9. Once done, select Background layer and change color.
10. Deselect background layer and then save the image (File>Save for Web, Format: PNG).