Black Liger - Possibilites
Moreover, another important concept is that even within the ligers, the black color does not come on the stripes. The color of the stripes on the ligers is usually dark brown. This color fades away as the ligers begin to age. Therefore, even the black transfer of the color into the ligers is highly doubtful as well. A total black colored liger will not even be possible to achieve. Therefore, the color of black color in ligers is very much less which further establishes very very meager chances of reproducing a black liger in the captivity. It also means that the hormonal structure of the ligers, does not permit them to produce enough black hair on their skin.
Black jaguars and black Leopards have been witnessed in our daily lives. But they will not help in reproducing a black liger in any circumstances at all. Therefore, the ligers will always remain in their current coloring and shape from the evidence which we have got. And rightly so there hasn't been any unusual colored liger from the sample of nearly 200 ligers from the last 200 years.
Hormonal Disturbance can change the pattern of the ligers from brown to black but that will be absolutely impossible, as no such evidence has been seen in real life especially within big cats. The last option to have a black liger will be to have black dyed liger, else black ligers have no existence in the natural world.