We used to argue about whether black was really a colour or not. Black is black. Dark. Full stop. With other colours, there is dark and light, like light red or dark red. That's not possible with black. It is the end of the scale, the superlative of dark. If I remember correctly, black is the colour that absorbs everything and does not reflect light or parts of the light spectrum like other colours do. Everything is absorbed, nothing comes back from black. Black is also often associated with mourning and some professions are traditionally dressed in black. Grief, pain and those things are often black: they absorb joy, happiness, lightness, enthusiasm, motivation and so on. Nothing comes back. At the other end is white - the opposite: everything is reflected, given back. White like the resurrection, the clothes worn by those who will be with us in eternity. Beautiful!
I wish you an extraordinary day!