If something if something absorbs blue light what color am i seeing

if something absorbs a blue/green light then that means it will appear to be yellow right?

blue and yellow are complementary colors ie they give white when mixed...may be you have watched that to remove yellow stains from white clothes people sometimes use blue(blue is the substance 's name too..),...so when something absorbs blue light you should see yellow....(but it depends on ones perception of colour and can vary)
green and magenta are complementary colours...