Oki C5150n Technical Reference Manual page 16

Natural Color
Monitor (6500K)/Perceptual
Optimized for printing photographs when using a monitor with a
color temperature of 6500K, This is best for printing photographic
images.
Monitor (6500K)/Vivid
Optimized for printing bright colors when using a monitor with a
color temperature of 6500K. Ideal for office graphics and text.
Vivid or Digital Camera settings produce brightest colors.
Monitor (9300K)
Optimized for printing photographs when using a monitor with a
color temperature of 6500K.
Digital Camera
Optimized for printing photographs taken with a digital camera.
This tends to produce prints with lighter and brighter colors. For
some photographs, other settings may be better depending on
the subjects and the conditions under which they were taken.
Vivid or Digital Camera settings produce brightest colors.
sRGB
Optimized for matching specific colors, such as a company logo
color. This option attempts to simulate RGB color. The colors
within the printer's color gamut are printed without any
modification, and only colors that fall outside the printable colors
are modified.
Unadjust
Undoes any color setting adjustments you have made.
OS X Printer Driver: • 16