If you keep this dust free it will be ready anytime that you need it. Paper towel or napkin to blot the paintbrush. Painting Yellow gold Base is yellow ochre. Shadow is burnt umber. Silver or Platinum Base is permanent white and neutral tint.
Highlight is permanent white.
Outline edges with neutral tint. Rose gold Apply a light wash of red watercolor over the yellow. Green gold Apply a wash of green watercolor over the yellow. When applying the wash use a very thinned out watercolor and a light touch with an almost dry brush so that you don't smear previous work. When painting always envision the light coming from the upper left corner or the upper right corner whichever is more comfortable to you.