We present an empirical investigation of the colors of quasars in the Sloan Digital Sky Survey ( SDSS ) photometric system .
The sample studied includes 2625 quasars with SDSS photometry : 1759 quasars found during SDSS spectroscopic commissioning and SDSS followup observations on other telescopes , 50 matches to FIRST quasars , 573 matches to quasars from the NASA Extragalactic Database , and 243 quasars from two or more of these sources .
The quasars are distributed in a 2.5 degree wide stripe centered on the Celestial Equator covering \sim 529 square degrees .
Positions ( accurate to 0.2 \arcsec ) and SDSS magnitudes are given for the 898 quasars known prior to SDSS spectroscopic commissioning .
New SDSS quasars , which range in brightness from i ^ { * } = 15.39 to the photometric magnitude limit of the survey , represent an increase of over 200 % in the number of known quasars in this area of the sky .

The ensemble average of the observed colors of quasars in the SDSS passbands are well represented by a power-law continuum with \alpha _ { \nu } = -0.5 ( f _ { \nu } \propto \nu ^ { \alpha } ) and are close to those predicted by previous simulations .
However , the contributions of the “ small blue ( or 3000 { \AA } ) bump ” and other strong emission lines have a significant effect upon the colors .
The color-redshift relation exhibits considerable structure , which may be of use in determining photometric redshifts for quasars from their colors alone .
The range of colors at a given redshift can generally be accounted for by a range in the optical spectral index with a distribution \alpha _ { \nu } = -0.5 \pm 0.65 ( 95 % confidence ) , but there is a red tail in the distribution .
This tail may be a sign of internal reddening , especially since fainter objects at a given redshift tend to exhibit redder colors than the average .
Finally , we show that there is a continuum of properties between quasars and Seyfert galaxies and we test the validity of the traditional dividing line ( M _ { B } = -23 ) between the two classes of AGN .