Actually, SDSS’s images do not quite represent what you would see with your eyes. Astronomers make color images by combining three monochromatic images, using an image from one wavelength for red, one for green, and one for blue. The SDSS uses the image from the green (g) filter for the blue part of the color image, the red (r) filter for the green part of the color image, and the near infrared (i) filter for the red part of the image/
The resulting full-color images look similar to what you would see with your eyes, but not exactly the same.
