The black orchid may, technically, be more of a dark-purple-brown than black. Because of this, some argue that there is no such thing as a black orchid. According to Orchid Mania, the black orchid doesn’t exist; however, some orchids are so dark in color that they can pass for black.
The orchids are actually dark brown or maroon, including the Australian native orchid, which is a rich, dark maroon, with a touch of purple and white.
Orchid Mania says the original black orchid is an erect monopodial species that climbs and is called trichoglottis brachiata. This orchid features a markedly purple lip and is velvety in texture and dark maroon.
The lips of what many consider the black orchid resemble the value of a clam shell. The leaves are greenish-yellow and spotted with purple dots. Some say the black orchid approximates an octopus, based on its trailing tentacles
If you want to refer to your almost black orchid as such, there is no harm in that. It has been done for years.