Answer
White light. No light.
Work Step by Step
Only blue light is transmitted through the blue filter.
Only yellow light is transmitted through the yellow filter.
The overlapping beams produce white light because they are complementary colors: yellow + blue = white (page 509).
When blue and yellow panes of glass are both placed in front of 1 flashlight, little or no light will be transmitted.
White - yellow - blue = zero light.
