You adjust the photo color by changing the color for each channel that composes a photo. By dragging the slider for each channel, you can adjust the photo's color. The larger the value, the stronger the color channel becomes. The lesser the value, the weaker it gets. You can enter the desired value on your own to fine tune the strength of the color for each channel.
You can adjust the color on the darkest of the photo.
You can adjust the color on the middle tone of the photo.
You can adjust the color on the brightest of the photo.
You can prevent changing the luminosity values in the photo while changing the color.