The answer is (c): the region of overlap is red, as seen in the photograph at the right below.
Note from Question #193 that a magenta filter (at left) removes the green and a yellow filter (right) removes the blue. Therefore the remaining light must be red. Another way of viewing this is that both yellow and magenta light includes the color red.
Below are two other pairs of negative color filters set up as done here: cyan and yellow at the left, and cyan and magenta at the right. (The cyan actually looks more cyan than in the pictures!)
What will be the color at the center when these two pairs of filters are overlapped? Click here when you have reached your conclusion and would like to check your answer.
