web page design – background for black and white graphic

I often like to use something like # f5f5f5 / # f1f1f1 as a light gray background: this allows white to stand out a little (even subtly). Then I can add a subtle shadow or border to the white object and it actually appears (testimonials here, for example, https://zudu.co.uk/). Something similar may work here, but I'm not sure if the shadows will work on the bars they touch.