Which words are readable, red words on white paper in red light or blue words on a white paper in red light, give a reason

Blue words on a white paper in red light.

Explanation:

The words that will be readable would be the words written in blue color on white paper in red light. It is because the words written in blue will look dark in red light and will be readable. Whereas, words written in red on white paper in red light will not be readable as red letters would also look red.

When red light is shone on a white paper (which reflects all colors) on which letters are written in blue, the blue color would absord the other colors and would reflect 'dark' color (blackish). Whereas words written in red on white paper would absorb the red light completely, thus reflecting red color only, making the words unreadable.

So, the correct answer would be blue words written on white paper in red light would be readable.