<｜begin▁of▁sentence｜>### Instruction:
Given a color palette with red, green, and blue, how can you use CairoPaletteDrawer in igraph to draw distinct colored shapes on a cairo context, and save it as a PNG image?
### Response:
import igraph as ig
import cairo

# Create a graph
g = ig.Graph.Full(3)

# Define the size of the image
width, height = 200, 200

# Create a Cairo Image Surface to draw on
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
ctx = cairo.Context(surface)

# Instantiate CairoPaletteDrawer with the cairo context
drawer = ig.drawing.CairoPaletteDrawer(context=ctx)
drawer.bbox = (width, height)

# Example usage of the drawer to draw palettes
palette = ig.drawing.colors.Palette(['red', 'green', 'blue'])
for idx, color in enumerate(palette):
    drawer.draw(color, [(idx * 50 + 50, 100), (idx * 50 + 30, 150), (idx * 50 + 70, 150)])

# Save the drawing to a file
surface.write_to_png('palette_drawing.png')
<|EOT|>
