Learn how to make a photo black & white and keep one color visible in Photoshop. This effect is sometimes called "selective color isolation".
In this 2-minute video, we will use Photoshop's Select Color Range feature to select the yellow shades of an image. We will then use a Black & White adjustment layer to turn everything else black and white.
Image reference (affiliate): https://1.envato.market/kjXYAx