What is a color guide?
Color guides were instrumental in the production of comics before computers. The sheets were printed with the line art and then given to colorist to complete with watercolors or inks. Colorists not only brought each page to life with their artistry, but they were also responsible for making sure that they properly coded each part of the page. The codes (YRB) indicate the different percentages of Yellow, Red and Blue that would be needed to produce the desired colors when printed.