How to change background color to one that works
Start from contrast. A pale subject such as a white sneaker or blond hair disappears on a light backdrop, and a navy jacket disappears on navy; aim for a background clearly lighter or darker than the edge of the subject.
Then think about where the image will sit. Soft, low-saturation colors (light gray, cream, pale blue) keep attention on the product and suit catalogues. Saturated colors grab attention and suit thumbnails and banners, but they also reflect a little onto skin in the eye's perception, so check that faces still look natural.
