When painting on black, basecoating with white helps give a brilliant glow to the finished picture.
It takes a while to decide what to paint. It takes another bit of time to sketch what is in my mind.
But once the sketch is done, transferring it to the item isn't time-consuming, nor is base coating in white.
Orange is my next color to add, but I have to wait until the white is dry. Since I'm using acrylics, the drying time isn't long.