Color sliders are one of the most underexposed subjects in black and white photography. Some people wonder what to do with black and white photography. We are going to tell something more about this.
As you can see in the title image, Silver Efex, but also other software, has color sliders with the colors red, yellow, green, cyan, blue and violet. There are programs with slightly fewer sliders, but the pricipe is the same. At the slider you will see a percentage indication that indicates how light or dark the color is displayed in black and white. Positive is lighter, negative is darker. So you can control how light or how dark a particular color is displayed in black and white.
Certain colors are often used to add or remove accents. For example with a portrait. If you lighten the red color, a person's skin appears more even. On the other hand, if you set it darker, you will see all the characteristic grooves and wrinkles. Blue is used to give the sky an accent in black and white. In many dramatic black and white landscapes, the blue color is set dark. So it is not that a certain color is regulated, but how light or how dark it is displayed in the black and white photo.
As an example the photo above. In addition to the backlighting, the blue level is probably also darker. This can be seen in the dark sky. The other colors probably needed little adjustment due to the backlight.
The effects can be very surprising, it is worth experimenting with these color levels. You are really playing with light, the true purpose of photography.