We can't see planets billions of light years away. The farthest planet directly imaged is at Beta Pictoris, 83 light years away. The imaged planet is 1700°F, thus radiates strongly in the infrared. The planet is also 8 times larger than Jupiter, which is ten times larger in diameter than Earth. Area goes by the square, so the imaged planet's area is 64,000 times bigger than Earth. The planet we are looking for in the outer reaches of the Solar System at 0.01 ly and about 6 times the Earth's size. We don't know what it's reflectivity is, but it is probably very low, similar to our Moon, which is basically coal black. Planet 9 is too dim, too small and too far away to see.