Convert png to svg using imagemagick and potrace

png2svg.sh

#!/bin/bash

if [ "$1" == "" ]; then
  echo Usage: $0 pngfile
  exit 0;
fi

FILE=`basename $1 .png`

if [ ! -e $FILE.png ]; then
  echo $FILE.png does not exist
  exit 1;
fi

convert $FILE.png $FILE.pnm
potrace -s -o $FILE.svg $FILE.pnm
rm $FILE.pnm

convert infile.png pnm:- | potrace -s -o outfile.svg

Hi, I have a question. When I convert it, it converted a RGB image to a BlackWhite SVG. How could I correct this?
thank you!

Cant convert coloured PNG to SVG, produced svgs are BW