When printing Barcode, the colour of both the print and media is an important consideration.
Chart 1 : shows combinations of colors that have enough contrast
(more than 63%) to be scanned.
Chart 2 : shows colors that should not be used because either they
do not have enough contrast or they can not be read by the scanner.
The darker color on the bar-code must be able to be seen through
WRATTEN 26 red filter. (It is a red filter similar to that used
in three dimensional glasses.)