Canon LBP312 SERIES User Manual page 441

<sRGB>
Color data is converted to black-and-white data to generate color-conscious smooth gradation.
<NTSC>
Color data is converted to black-and-white data to generate appearances equivalent to television pictures
(NTSC).
<Uniform RGB>
Color data is converted to black-and-white data to equalize all RGB levels based on the brightness only.
Setting Menu List
435