My product shot images to be recoloured

I currently have one products for sale. We are wanting to know what the demand will be like with more colours.

I need someone to please re colour the stitching on the products in 4 colours please. It would have to look great so as if the photoshoot was done with the pants with that coloured stitching on.

All in all i need 4 colours to be done but two types of products, and 5 pictures for each colour. So 40 pictures all together.