Dull; stupid.
Causing someone to fall sleep or feel sleepy; lulling; soporific.
Boring.
Inclined to drowse; heavy with sleepiness
Plain, dull, lifeless.
Having only one color, represented by differing hues and tints. For example shades in a black and white television.
Perceptive of only one color; unable to distinguish colors; total color blindness.