I've always preferred them to black digits on a gray/green background and have 3 models. I think I fell in love with the look of them when I first saw them some 25 to 30 years ago. I think Casio brought them out first but I could be wrong. My other Casio is black digits, though. Only on my Rado do I find difficulty in reading them when the light is low because it doesn't have a backlight function.