I want to know the colour of copper powder. Is it light green in colour?

Answer:
Copper powder is the colour of copper, a shiny salmon pink. When the powder sits in air it darkens as it oxidizes. As the thickness of the oxide layer increases the colour changes from shiny pink to a darker red to bronze to black, when the colour depends on the thickness of the oxide layer in the order of nanometers and you see the colour of the refracted light. When the layer of oxides on the powder is so thick the colour of the oxide is predominant you could see a light green colour. This would be similar to seeing rusty dark brown iron powder after exposure to air and oxidizing atmospheres.