In a dark room, blue, yellow and red sheets of paper lie on the table. what light should

In a dark room, blue, yellow and red sheets of paper lie on the table. what light should be used to illuminate the yellow leaf so that it is seen brightest of all

Since the leaf itself is yellow, then for its better vision, you need to illuminate the leaf either with the same yellow color or white, but this is not so important. In any case, under different light of the two colors, a yellow leaf will reflect better light than blue and red. And since it reflects light better, then it will be seen better than the other two colors. Blue and red, by themselves, are dull colors, which means that this particular reason will not give the desired reflection and will be seen worse.