In red light a blue object appears black because there is no blue light for it to reflect, while black resembles the absence of all color.
(a blue object; appears; because there is no blue light for it to reflect, while black resembles the absence of all color; L:In red light) (it; to reflect; ) (black; resembles; the absence of all color)
a blue object it black
appears to reflect resembles
because there is no blue light for it to reflect, while black resembles the absence of all color L:In red light
the absence of all color