LEARNT: keep asking is it a cool or warm 'grey', light or dark. This is the key to watercolours. Don't ask what colour is it and use the tube names. You could use any colors. Colour is not important - cool or warm is important and VALUE is important:
美濃国養老の滝 Hokusia born 1760 in Japan, beautiful wood block prints. Most famous for "The Great Wave off Kanagawa"